• Authors
  • Department of Applied Social Sciences, The Hong Kong Polytechnic University, Hong Kong, China
  • Division of Learning, Development and Diversity, Department of Education, Faculty of Education, The University of Hong Kong, Hong Kong, China
  • Department of Applied Social Sciences, The Hong Kong Polytechnic University, Hong Kong, China

Internet Addiction


The Internet has become a basic tool for trading, entertainment, communication, as well as education in the contemporary world. Nevertheless, despite the high speed of information flow and potential educational value of the Internet, there are several attributes of the Internet which may foster addictive behavior. These attributes include easy and flexible access 24 hours a day; anonymity; provision of free, diversified, and unlimited number of social networks without geographical boundaries; greater control over one's self-presentation; and provision of numerous opportunities to fulfill the need for belongingness as well as to escape from emotional difficulties, problematic situations, and personal hardships.

Internet addiction commonly refers to an individual's inability to control his or her use of the Internet (including any online-related, compulsive behavior) which eventually causes one's marked distress and functional impairment in daily life. Research findings have shown that excessive use of Internet or Internet addiction adversely affects one's physical health, family life, and academic performance. Concerning the negative consequences of Internet addiction on one's physical health, persistence of sleep deprivation may harm one's immune system, thus increasing one's vulnerability to assorted diseases. The lack of exercise due to excessive use of computer by maintaining a sitting posture may also risk suffering from carpal tunnel syndrome, back pain, and eyestrain. Concerning family problems caused by Internet addiction, family relationships are seriously disrupted by Internet addicts due to the decrease in time spending with family, reluctance of performing family duties such as doing household chores, and increase of conflicts with family in the negotiation for time spent on the Internet. Academic problems caused by Internet addiction include decline in study habits, significant drop in grades, missing classes, increased risk of being placed on academic probation, and poor integration in extracurricular activities. Besides, adolescent Internet addicts often suffer from severe psychological distress, such as depression; anxiety; compulsivity; feeling of self-effacement; fear that life without Internet would be boring, empty, and joyless; as well as feeling of loneliness and social isolation. In addition, people addicted to the Internet games may excessively imitate the behaviors and values of the characters in online games.
In view of the possible negative influence of Internet addiction on human development, there is a need to have a thorough understanding of the nature of Internet addiction. There are several sections in this chapter. First, a historical review of Internet addiction is presented. Second, the conceptualization and assessment of Internet addiction are discussed. Third, prevalence data of Internet addiction are described. Fourth, major theoretical accounts of Internet addiction are presented. Fifth, risk factors and protective factors related to Internet addiction are discussed. Sixth, intervention models of Internet addiction are outlined. Finally, the future research directions are examined.
ADHD Attention deficit hyperactivity disorder - APA American psychological association - CBT Cognitive-behavioral therapy - DSM-IV Diagnostic and statistical manual (4th edition) of the American Psychiatric Association - DSM-V Diagnostic and statistical manual (5th edition) of the American Psychiatric Association - IA Internet addiction - IAD Internet addiction disorder - IAT Internet addiction test - ICD Impulse control disorder - IRABI Internet-related addictive behavior inventory - ITAA Internet and technology addiction anonymous - MI Motivational interviewing - OARS Open-ended questions affirmations, reflective listening, and summarization - OCD Obsessive-compulsive disorder - PCU Pathological computer use - PIU Problematic Internet use - PIUQ Problematic Internet Use Questionnaire - RtC Group therapy treatment with a combination of readiness to change - SSRI Selective serotonin reuptake inhibitor

Brief History

Historical Development

The initial idea of Internet as a way of "data communication" was first proposed in the early 1960s by a group of American computer scientists who saw great potential value in allowing scientists to share information on research and development in scientific fields via computers. During the 1980s, the use of Internet developed quickly, and by 1995 the Internet had become a mainstream communication vehicle (Shaffer et al. 2000). From then on, as with the functionality of Internet, the number of Internet users has expanded dramatically across the world. Today, as a collection of various services and resources, the Internet has become the most ever powerful tool for human being. Just as a popular saying goes, "Internet has brought a globe in a single room, and even the palm of one's hand."

While it is evident that the Internet has greatly altered modern lives by its accessibility and convenience, possible misuses and destructive effects of the Internet have not gone unnoticed. The presence of addictive behaviors among some Internet users has drawn the attention of the public and helping professionals since the early 1990s. Research into the potential problems of excessive Internet use has increased substantially over the past two decades.

In 1995, an article entitled "The Lure and Addiction of Life On Line," published in the New York Times, first raised the concerns of a wider public about the potential harms of uncontrollable Internet use. By quoting addiction experts and computer industry professionals, the author linked excessive Internet use with other behavioral addiction such as compulsive gambling, shopping, and substance abuse. In the same year, Ivan Goldberg borrowed criteria for defining psychoactive substance dependence in the DSM-IV and first coined the term "Internet addiction disorder" to represent those having problematic Internet use behavior. In June 1996, an article first appeared in the American Psychological Association's trade newspaper, the APA Monitor, described cases of college students who suffered from academic failure and poor social relationships due to Internet misuse. In this article, Bridget Murray cautioned that the Internet might potentially lead to addictive behaviors among users and suggested the psychology community to develop guidelines for treating people who may be addicted to the Internet (Murray, 1996).

Similarly, as a leading expert in the field of problematic Internet use behavior, Kimberly Young presented the first empirical research on Internet addiction in 1996 at the American Psychological Association's annual conference in her paper entitled "Internet Addiction: The Emergence of a New Disorder." In this paper, Young adapted the criteria for pathological gambling defined by the DSM-IV (American Psychiatric Association, 1994) to diagnose the Internet addiction as a compulsive disorder. Young also developed the 7-item, 8-item, 10-item, and 20-item scales, namely, the Internet Addiction Test, for assessing "Internet dependent" or "Internet addicted" behavior. In one of her early studies with a sample of 596 self-selected Internet users, Young found that 66% of the respondents could be classified as "Internet dependent," who displayed an array of addictive behaviors including tolerance, loss of control, withdrawal, and impairment of functioning. Among these identified individuals, negative academic, social, financial, and occupational consequences caused by Internet addiction were also observed. Based on these findings, Young pointed out that Internet addiction adversely affected one's physical health, family life, and academic performance and ought to be designated as a mental disorder. Since then, a lot of research and debates about Internet addiction have been generated.

Griffiths regarded Internet addiction as a form of technological addiction under the category of behavioral addiction. He proposed six core components of Internet addiction, including salience (Internet dominates one's life), mood modification (Internet changes the mood of the user), tolerance (increasing time spent to obtain the desired effect), withdrawal symptoms (unpleasant physical and psychological reactions when Internet activity is reduced or curtailed), conflicts (intraindividual and interindividual conflicts because of Internet behavior), and relapse (tendency to revert to earlier pattern of addictive behavior). Young described how Internet addiction is akin to substance addiction through providing a self-medicating effect, allowing for avoidant behaviors and brief emotional relief. She also proposed four types of triggers that serve as the initiation of excessive Internet use: (1) applications: a specific function of Internet that is particularly problematic for the user; (2) emotions: being online is gratifying and calming while blocking pain, uncertainty, or discomfort; (3) cognition: being online is a relief from maladaptive thoughts and catastrophic thinking; and (4) life events: dissatisfaction with one or multiple areas of life. Singularly or in combination, these conditions could lead a person to be more prone to Internet addiction.

In addition to Young's Internet Addiction Test, there are other attempts to construct Internet addiction measurements. For example, Brenner developed a 32-item questionnaire entitled "Internet-Related Addictive Behavior Inventory" (IRABI) to assess Internet addiction and found that most of the respondents experienced at least one of the Internet addiction symptoms, including tolerance, craving, and withdrawal. Egger and Rauterberg also designed a self-reported questionnaire to examine Internet behaviors and addiction tendency of 454 Internet users in Switzerland and other European countries, and reported that 10.6% of the respondents were addicted to or dependent on the Internet.

Different terms have been used to describe Internet addiction problems, such as problematic Internet use (PIU), pathological computer use (PCU), and Internet addiction disorder (IAD). The Centre for On-Line Addiction (1998) identified five specific types of Internet addiction:
  1. Cybersexual addiction - Addiction to cyber-pornographic materials and interaction (such as adult chat rooms)
  2. Cyber-relationship addiction - Addiction to online friendship which replaces one's relationships with friends and family in real life
  3. Net compulsion - Obsessive online activities including online gambling, online auction, and online trading
  4. Information overload - Obsessive web surfing or searches of databases
  5. Computer addiction - Excessive computer game playing or efforts paid to computer programming

Intervention for Internet Addiction

Research studies in the Western and Asian contexts have also suggested that the risk of Internet addiction is rising especially among young people. In response to the negative consequences and the increasing risk of Internet addiction, there is a need to explore intervention models to help Internet addicts. Over the years, an array of therapeutic strategies has been developed to treat Internet addiction based on different theoretical foundations. The first treatment facility designed to specifically deal with Internet addiction is Kimberly Young's Center for Internet Addiction Recovery, founded in 1995. The center offers visitors educational resources on Internet addiction; a set of online self-assessment tools to determine whether one has Internet addiction; and different forms of counseling services for self-identified Internet addicts, including both face-to-face counseling for individuals, couples, and families and e-counseling through telephone and online communication. The major treatment strategy adopted in the center is the cognitive-behavioral therapy plus psycho-education. In addition, seminars and workshops are provided in the center to train mental health practitioners in diagnosis, clinical assessment, and treatment of Internet addiction.

Some important research and treatment work has been conducted in South Korea, China, and other Asian areas. After a series of 10 cardiopulmonary-related deaths induced by compulsive Internet use in Internet bars and a game-related murder, South Korean government views Internet addiction as one of its most serious public health issues and starts to carry out substantial research on Internet addiction. China has also shown great concerns about the disorder because of the dramatic increase of Internet use among Chinese adolescents in the last decade. According to a national report in 2007, there are around 10 million Chinese teenagers who meet Internet addiction diagnostic criteria. As a result of the considerable attentions given to this problem, South Korea and China have officially recognized and treated Internet addiction as a psychiatric disorder. In South Korea, the government has trained 1,000 counselors to specifically help the 200,000 children believed to be addicted to the Internet. Similarly, Chinese government has officially designated hospital psychiatric units and Internet addiction recovery centers to treat cases of Internet addiction since 2008.

Contrasting with the active efforts to address the problems related to Internet addiction in Asian countries, Internet addiction has not been recognized as a separate disorder by the American Psychiatric Association and the treatment is generally not covered by medical insurance. Although research shows that Internet addiction is a concerning psychological impairment, with regard to whether Internet addiction should be diagnosed as a mental disorder, there have been considerable debates among Western researchers. Some experts insisted that excessive use of Internet is a secondary manifestation of other mental disorders to counteract other psychological deficiencies or to fulfill other psychological needs associated with underlying disorders. Consequently, Internet addiction is symptomatic in nature, which should not be considered as a true addiction or a specific disorder. On the other hand, an increasing number of clinicians and psychologists support for the inclusion of Internet addiction as a real disorder in DSM-V. They pointed out that symptoms of Internet addiction mirror other compulsive/impulsive disorders, including excessive use, withdrawal, tolerance, and negative repercussions, akin to other addictive disorders in that some Internet services (like online shopping, gambling, and sex) have unique psychological properties which induce dissociation, time distortion, and instant gratification that can produce a mood-altering effect, and more importantly, excessive Internet use has directly caused severe functional impairments in different aspects of the users' lives. Therefore, Internet addiction is worthy of a standardized definition and of diagnostic criteria.

Now, the American Psychiatrist Association is considering the inclusion of Internet addiction in the new revision of the DSM-V, and there has been a general recognition among clinical practitioners that patients having difficulties in controlling their impulses to use the Internet need to be treated no matter how this behavior is classified. Despite of this, the continuous controversy has inevitably hindered the development of effective treatment protocols specifically designed for Internet addictive patients. For example, patients may not be able to receive a systematic treatment program because they cannot afford the therapeutic fee which is not covered by their medical insurance.

Over the years, hospitals and clinics have emerged with outpatient treatment services for Internet addiction recovery, and in some cases addiction rehabilitation centers have admitted people with Internet addiction into inpatient care. Social service organizations and college campuses have also started intervention programs and support groups to help youth and students who are addicted to the Internet. In 2009, the first residential treatment center for Internet addiction in the United States, called reSTART, was opened in the suburb of Seattle. The reSTART offers a 45-day abstinence-based recovery program for people with pathological computer use. Sessions of the program range from individual and group counseling and psychotherapy to life skills and vocational coaching, physical education, and a variety of recreational activities. A few treatment procedures have been developed to help people with Internet addiction, including group therapy treatment with a combination of readiness to change (RtC), cognitive-behavioral therapy (CBT), motivational interviewing (MI) interventions, as well as reality therapy group counseling program. Some of the programs were developed to help clients with specific Internet addiction, such as Internet-addicted sexual behavior, and the protocols of those programs were not presented in details. Young reported that cognitive-behavioral therapy techniques were effective in decreasing the addictive thoughts and behaviors related to Internet both in the short-term assessment and 6-month follow-up. Clearly, more experimentally designed evaluative studies that employ randomized control groups are needed to demonstrate the effectiveness of different intervention programs.

Relevant Journals and Websites

Since the inception of the term, Internet addiction has been a hot topic not only in the mass media but also in the scientific community. Research findings on Internet addiction are widely reported in a variety of academic publications across multiple disciplines ranging from psychiatry, psychology, social work, education, to laws, economics, and even computer sciences. In the field of psychiatry, several highly prestigious journals, such as "The American Journal of Psychiatry," "Psychiatrist," and "Advances in Psychiatric Treatment," publish Internet addiction studies, reviews, and editorials. In the broad area of social sciences, such findings frequently appear in "CyberPsychology & Behavior" (now the "CyberPsychology, Behavior, and Social Networking"), "American Psychologist," "Addictive Behaviors," "Journal of School Health," "Psychiatry, Psychology, and Law," "Educational Psychological Review," and others. Another information dissemination outlet of Internet addiction research consists of computing journals such as "Computers & Education," "Computer in Human Behavior," and "Journal of Human Computer Studies." Among all these journals, "CyberPsychology & Behavior" is now the leading publication for Internet addiction research, aiming at exploring the impact of the Internet, multimedia, and virtual reality on behavior and society. There are also a few websites providing useful information, resources, therapeutic services, or referral sites for people who might be addicted to Internet, their friends and family, and practitioners who work on Internet addiction, such as the following:
  1. The Centre for Internet Addiction Recovery (http://www.netaddiction.com)
  2. Virtual-Addiction (http://www.virtual-addiction.com/)
  3. The reSTART Internet addiction recovery Program (http://www.netaddictionrecovery.com/)
  4. Illinois Institute for Addiction Recovery (http://www.addictionrecov.org)
  5. Daily Strength (http://www.dailystrength.org/c/Internet-Addiction/support-group)
  6. Computer Addiction Services (http://www.computeraddiction.com)
  7. Psych Central (http://psychcentral.com/netaddiction/)

Conceptualization of Internet Addiction

Since Ivan Goldberg borrowed the criteria of substance abuse in DSM-IV to define the "Internet addiction disorder" in 1995, there have been many debates on whether Internet addiction should be regarded as a psychiatric disorder and how it should be assessed. While some researchers link Internet addiction to obsessive-compulsive disorder (OCD) and impulse control disorder (ICD), there are views arguing that IA does not deserve its own diagnostic criteria due to the difficulty on determining whether IA develops on its own or not. Besides, while some researchers suggest that there are similarities between Internet compulsion and compulsive gambling, some argue that it might be more appropriate to use the term "problematic" or "maladaptive" to describe Internet overuse. Some even argue that people would go from overuse to "normal" use eventually, while the overuse is only a transition phase. Other views suggest that one must be very careful to draw a line between "normal overenthusiasm" in using the Internet and "abnormal preoccupation" with Internet use.

There are several issues intrinsic to the conceptualization of Internet addiction as a form of mental problem. First, in terms of diagnostic criteria, it is important to ask whether there is a consistent set of symptoms and syndromes that are observed and diagnosed. Second, the question of whether the diagnostic criteria demonstrate validity should be asked. Third, it is important to ask whether Internet addictive behavior should be seen as a separate mental disorder or part of a specific form of mental disorder. There are research findings showing that problematic Internet use is associated with other forms of mental disorders such as obsessive-compulsive disorder and depression. Regarding such observed relationships, there are several possibilities. First, psychiatric symptoms may lead to the occurrence of problematic Internet use. Second, Internet addiction may lead to the onset of psychiatric symptoms. Third, psychiatric symptoms and problematic Internet use may influence each other. Finally, the relationship between the two domains may be due to shared genetic or environmental factors.

Generally speaking, concepts such as compulsive use, tolerance, withdrawal, and impairment of psychosocial functioning, particularly those related to substance abuse and impulse control disorders, are used to define Internet addictive behavior. Internet addiction has been understood in terms of drug addiction and pathological gambling in the Diagnostic and Statistical Manual (4th edition) of the American Psychiatric Association. In the DSM-IV, substance abuse is defined as a maladaptive pattern of substance use which leads to significant impairment or distress, as shown by one or more of the following behaviors occurring within a 12-month period: (1) failure to fulfill major role obligations at work, school, or home due to recurrent substance use (e.g., impaired work performance or absences because of substance use, impaired school performance or absences related to substance use, home management problems as a result of drug use); (2) using substance in situations in which it is physically dangerous (e.g., driving an automobile under the influence of drugs); (3) recurrent legal problems because of taking drugs; or (4) although substance abuse has caused persistent or recurrent social or interpersonal problems, the person still uses drugs.

Translating the above criteria to Internet abuse, Internet abuse can be understood as a maladaptive pattern of Internet use which leads to significant impairment or distress, as shown by one or more of the following behaviors occurring within a 12-month period: (1) failure to fulfill major role obligations at work, school, or home (e.g., impaired work performance or absences because of Internet use, impaired school performance or absences because of Internet use, home management problems as a result of Internet use); (2) using Internet in situations in which it is physically dangerous (e.g., continuous and prolonged use of Internet without rest, long duration of stay in Internet bars); (3) recurrent legal problems because of using Internet (e.g., illegal downloading and Internet stealing); or (4) continuous use of Internet despite the persistent or recurrent social or interpersonal problems caused by Internet abuse.

Substance dependence is a more serious problem compared to substance abuse, which is accompanied by certain changes in the way the person uses substance. According to DSM-IV, substance dependence (or addiction) refers to a maladaptive pattern of substance use which leads to clinically significant impairment or distress, with the person displaying three or more of the characteristics in the same 12-month period. The characteristics include (1) tolerance as shown by either a need to increase the amount of the substance to achieve the desired effect or experiencing diminished effect with continued use of the same amount of the substance; (2) withdrawal symptoms, as manifested by either the characteristic withdrawal syndrome for the substance or taking the same (or closely related) substance to relieve or avoid withdrawal symptoms; (3) amount of drug taken or period of taking is greater than what is intended; (4) the person has a persistent desire or unsuccessful effort to cut down or control substance use; (5) much time is spent to obtain or use the substance or to recover from its effect; (6) substance abuse has led to the giving up or reduction of important social, occupational, or recreational activities; and (7) continued drug use despite knowing that drug use has caused a persistent or recurrent physical or psychological problem.

Translating the above characteristics of substance dependence in DSM-IV to Internet addiction, Internet dependence can be defined as a maladaptive pattern of Internet use which leads to significant psychosocial impairment or distress, with the person displaying three or more of the characteristics in the same 12-month period. The characteristics include (1) tolerance as shown by either a need to increase the time spent on the Internet to achieve the desired effect or experiencing diminished effect with continued use of the same amount of Internet-related time and activities; (2) withdrawal symptoms; (3) amount of time and effort spent on the Internet is greater than what is intended; (4) the person has the desire to control Internet use or unsuccessful effort to cut down; (5) much time is spent to get access or use the Internet or to recover from its effect; (6) Internet use has led to the giving up or reduction of important social, occupational, or recreational activities; and (7) continued Internet use despite knowing that Internet use has caused a persistent or recurrent physical or psychological problem.

Besides drug addiction, pathological gambling has also been used by theorists to understand the nature of Internet addiction. In the DSM-IV, there are two diagnostic criteria for pathological gambling. First, it is characterized by persistent and recurrent maladaptive gambling behavior as indicated by five or more of the following signs: (1) preoccupation with gambling such as reliving past gambling experiences or thinking of ways to get money for gambling purpose; (2) need to gamble with more money in order to achieve the desired excitement; (3) experiencing repeated unsuccessful efforts to control, cut back, or stop gambling; (4) to cut down or stop gambling will lead to restlessness or irritability; (5) using gambling as a way of avoidance of problems or relief of dysphoric mood; (6) chasing after losing money; (7) lying to others to cover up the extent of involvement with gambling; (8) engaging in illegal activities to finance gambling; (9) adverse impact or loss of a significant relationship, job, or educational or career opportunity because of gambling; and (10) relying on others to provide money to cope with a desperate financial situation caused by gambling. The second criterion is that the gambling behavior is not better accounted for by a manic episode. These criteria were often employed/adapted by researchers in developing assessment tools and diagnostic criterion of Internet addiction.

Assessment of Internet Addiction

As far as assessment tools of Internet addiction are concerned, many instruments have been developed. Among the available measures, assessment tools developed by Ivan Goldberg and Kimberly Young are commonly used by researchers. According to these instruments, an individual is defined as Internet addict if he/she displays certain addictive behaviors in the past 12 months.

Young has developed several instruments assessing Internet addiction based on the concept of pathological gambling. The different versions are listed below.

Young's Brief 8-Item Questionnaire

According to Young, a person is considered "addicted" if he/she shows five or more of the following characteristics and when his/her behavior could not be better accounted for by a manic episode:
  1. Preoccupation with the Internet such as thinking about previous online activity or anticipating next online session
  2. Need to spend increasing amount of time online in order to achieve satisfaction
  3. Repeatedly unsuccessful efforts to control, cut back, or stop Internet use
  4. Suffering from withdrawal symptoms such as restlessness, moodiness, depression, or irritability when reducing Internet use
  5. Staying online longer than originally intended
  6. Internet use endangers or leads to the loss of significant relationship, job, or educational or career opportunity
  7. Telling lies to cover up problems created by Internet addiction
  8. Use of Internet to escape from problems or relieve from a dysphoric mood

Young's 10-Item Questionnaire

A person is defined as "Internet dependent" if he/she shows four or more of the following attributes:
  1. Feeling preoccupied with the Internet or online services and thinking about it while off-line
  2. Feeling a need to spend more and more time online to achieve satisfaction
  3. Being unable to control online use
  4. Feeling restless or irritable when attempting to cut down or stop online use
  5. Going online to escape from problems or relieve feelings such as helplessness, guilt, anxiety, or depression
  6. Lying to family members or friends to conceal excessive Internet use
  7. Risking the loss of a significant relationship, job, or educational or career opportunity because of online use
  8. Keeping on using the Internet even after spending too much money on online fees
  9. Showing withdrawal when off-line, such as increased depression, moodiness, or irritability
  10. Staying online longer than originally intended

Young's 7-Item Questionnaire

A person is defined as "Internet dependent" if he/she shows three or more of the following characteristics:
  1. Experiencing tolerance in that one needs for increased amounts of Internet use to achieve the desired effect or there is a diminished effect with continued use of the same time spent on the Internet
  2. Spending longer periods of time on the Internet than intended
  3. Spending a great deal of time in activities to stay online longer
  4. Giving up any social, occupational, or recreational activities because of the Internet
  5. Continuing to use the Internet despite knowledge of having a persistent or recurrent problem that is likely to have been caused or exacerbated by the Internet
  6. Having made unsuccessful attempts to cut down time spent online or lack of desire to cut down on the amount of time spent online
  7. Experiencing withdrawal symptoms (e.g., depression, irritability, moodiness, anxiety) when off-line
Besides Young, Goldberg also proposed seven criteria to assess Internet addiction by modifying the DSM-IV criteria for psychoactive substance dependence. A person is defined as having "Internet addiction disorder" if his/her Internet use behavior meets three or more of the following criteria:
  • Criteria I - Tolerance.
  • Criteria II - Withdrawal.
  • Criteria III - The Internet is accessed more often or for longer periods of time than was intended.
  • Criteria IV - There is a persistent desire or unsuccessful efforts to cut down or control Internet use.
  • Criteria V - A great deal of time is spent in activities related to Internet use.
  • Criteria VI - Important social, occupational, or recreational activities are given up or reduced because of Internet use.
  • Criteria VII - Internet use is continued despite knowledge of having a persistent or recurrent physical, social, occupational, or psychological problem.

There are other attempts to develop assessment tools of Internet addiction among researchers. Brenner designed a 32-item instrument, the Internet-Related Addictive Behavior Inventory (IRABI), for the measurement of Internet addiction. The items are devised to assess Internet use behaviors and experiences similar to those related to substance abuse defined in the DSM-IV. However, specific criteria to determine whether an individual is addicted to Internet were lacking in Brenner's study, and it is not clear whether items in the IRABI really capture behaviors that signify Internet addiction. In an online survey called the Virtual Addiction Survey, Greenfield (1999) used ten items adapted from DSM-IV criteria of pathological gambling to measure addicted Internet use patterns. Morahan-Martin and Schumacher (2000) developed a 13-item questionnaire to assess pathological Internet use in which those who answered "yes" to four or more of the 13 items were defined as pathological Internet users. Some of the items were akin to Brenner's IRABI items and thus were questioned similarly about the validity. Other researchers identify Internet addicts with one single self-reported item, for example, asking the participants the extent to which they agree or disagree with the following statement: "I think I might have become a little psychologically dependent on the Internet." Respondents are classified as "Internet dependent" if they chose "agree" or "strongly agree" to the statement (Kubey et al. 2001). This method could be very subjective because the single item only reflects one's self-perceived dependency on Internet without involving any behavioral symptoms of Internet addiction.

In conclusion, different conceptions and measurements of Internet addiction are presented in the literature. There are several observations. First, conceptualizations and definitions of Internet addiction, despite of its variations, basically derive from the diagnostic criteria of substance abuse and pathological gambling in DSM-IV. However, whether Internet addiction should be conceptualized as an impulse control disorder or an addictive disorder is still undetermined. Second, a wide range of assessment tools have been developed while the extent of reliability and validation varies across different measures. Third, clinical usefulness of the measurements has often been questioned. Fourth, the samples on which the instruments were developed were not representative enough. Most of the participants were selected from a particular population (such as university students) and were sometimes self-referred, which inevitably biased the results. Finally, inconsistent criteria have been used in different studies to diagnose Internet addiction, which makes it impossible to make comparison across studies. Therefore, it is the first priority for future researchers to develop a comprehensive definition of Internet addiction that can unify the current diverse conceptualizations and based on which to devise a standardized and psychometrically sound instrument to assess Internet addiction.

Prevalence of Internet Addiction

There are a growing number of prevalence studies on Internet addiction in different parts of the world in which different methodologies were used (Shek et al. 2009). In the United States, a national telephone survey (N = 2,513 adults with a response rate of 56.3%) showed that 5.9% of the respondents suffered from excessive Internet use, 3.7% felt preoccupied by the Internet when off-line, 13.7% found it was difficult to stay away from the Internet for several days at a time, and 12.4% was found to stay online longer than intended very often or often. In the United Kingdom, a study based on 371 randomly selected students showed that 18.3% of the sample was diagnosed as problematic Internet users.

Research studies in the Scandinavian counties suggest that the risk of Internet addiction among young people is increasing. In a study with a sample of 3,237 adolescents from Norway, it was found that 1.98% and 8.68% could be regarded as having Internet addiction and at risk of Internet abuse, respectively. Among the frequent Internet users, which accounted for 49.6% of the whole sample, the percentages of participants classified as Internet addicts and being at risk of Internet abuse rose to 4.02% and 17.66%, respectively. However, in another recent national research in Norway with a random sample of 9,638 individuals aged 16-74 years, only 35 respondents (0.36%) were classified as addictive Internet users. In a study with a sample of 7,292 adolescents from Finland, it was reported that 1.4% of girls and 1.7% of boys were classified as Internet addicts. Among the daily Internet users (26% of the respondents), 4.7% of girls and 4.6% of boys were categorized as Internet addicts.

There were a few Internet addiction prevalence studies conducted in Mediterranean countries. In a study in Turkey (N = 983), 38% of Internet users thought their Internet use might lead to an addiction, compared to 55% who did not. A study in Northern Cyprus showed that 1.1% and 11% of the respondents (N = 686) could be classified as having "pathological usage" and "limited symptoms" (i.e., great risk of pathological Internet usage), respectively. In South Africa, a study was conducted on a sample of university students (N = 1,795) using Young's Diagnostic Questionnaire for Internet addiction and a Problematic Internet Use Questionnaire (PIUQ) adapted from Young's 20-item Internet Addiction Test (IAT). It was shown that the prevalence of Internet addiction ranged from 1.67% to 5.29%, depending on different evaluative criteria used.

Prevalence studies on Internet addiction have also been carried out in Asian countries, including different Chinese communities. In a study examining Internet behavior in 2,620 high school students in mainland China, 2.4% of them were diagnosed as Internet addicts. In another study where 3,557 first-year university students in Shanxi were recruited, 6.44% of the respondents were classified as Internet addictive users. In Taiwan, a study with a sample of 1,708 high school adolescents showed that 13.8% of the respondents were identified as Internet addicts, who were found to have lower self-esteem, higher level of depressed mood and feelings of sadness, poorer interpersonal relationship, and negative self-concepts when compared to their nonaddicted counterparts. Chinese researchers have also tried to adapt existing Internet addiction scales for their use in Chinese culture and, meanwhile, develop indigenous instruments to specifically apply within Chinese context. In a study in Taiwan, researchers have developed and utilized a Chinese Internet-Related Addictive Behavior Inventory to examine the prevalence of Internet addiction on a sample of college students. Based on Young's criteria, 5.9% of the participants were categorized as Internet addicts. In the case of Hong Kong, Young's screening instrument for addictive Internet use was administered on a random sample of 976 adolescents and found that 37.9% can be identified as Internet addicts. In another study with a sample of 699 high school students, it was reported that a 3.9% rate of Internet addiction using Young's Internet Addiction Test was found. Besides, in a comparative study involving Chinese and US students, Chinese students rated significantly higher on different dimensions of Internet addiction than did US students, including time spent online and frequency of Internet use.

Substantial studies on the prevalence and correlates of Internet addiction have been carried out in South Korea due to the considerable concerns about the issue by the government. While most Korean studies employed a Korean translation of Young's 20-item Internet Addiction Test, different cutoff scores were utilized. Using a more lenient cutoff, a study reported an Internet addiction rate of 13.80% among elementary school students (N = 455) and a rate of 20.33% among high school students (N = 836). However, another study reported on a sample of 1,573 high school students that only 1.60% can be classified as Internet addicts by using a stringent cutoff criterion, and 37.9% of the respondents were considered as possible Internet addicts. Efforts were also made to develop indigenous instrument to assess Internet addiction. Lee and his associates devised a 40-item Korean Internet Addiction Test based on which they found 4% and 20.4% of the adolescent respondents (N = 627) were high-risk Internet users and potential-risk Internet users, respectively. With reference to adolescents identified as being at high risk, 28% of them did not recognize the degree of severity of Internet addiction, and 24% of them had difficulty in controlling the amount of time playing online game. In Japan (N = 242), a study using Young's Internet Addiction Scale test and criteria revealed that 9.1% of the sample can be diagnosed as Internet addicts.

To sum up, the prevalence figures of Internet addiction vary substantially across different parts of the world, ranging from 0.36% (in the Norwegian study) to 37.9% (in the Hong Kong study). There are several reasons that may account for the large varying rate of Internet addiction reported. First, different measures were used in different studies. While Young's Internet Addiction Test is most commonly employed, there are other newly developed instruments. Second, inconsistent cutoff criteria were utilized by different researchers to diagnose Internet addiction. Third, samples recruited in various studies were also different. This again points to a critical need of developing standardized measures for the assessment of Internet addiction, based on which the reported prevalence data can be meaningfully and validly compared. In addition, it is important to develop norms and cutoff scores for different populations through methodologically sound empirical studies.

Theories of Internet Addiction

Scientific theories play an important role in helping health professionals to understand the nature of Internet addiction and formulate intervention strategies. There are several functions of theories. First, they provide languages for health professionals to describe the phenomena related to Internet addiction (e.g., Internet addiction as a manifestation of personality problem or family problem). Second, theories help health professionals to explain and make sense of Internet addiction particularly with regard to its origin, maintenance, and treatment. Third, based on theoretical propositions, health professionals can predict Internet addiction behavior of the clients. Finally, theories have therapeutic implications regarding how Internet addiction can be treated and prevented. While theories provide "spectacles" through which health professionals look at the world, they also constitute blind spots if health professionals use them in an uncritical manner. Moreover, when using theories, it is necessary to understand the degree of empirical support for them and the extent to which the theories can be applied in real-life settings.

There are many theoretical perspectives from different disciplines of psychology and sociology that can be used to understand Internet addiction. These theories ranged from micro analyses (e.g., genetic explanation of Internet addiction) to macro analyses (e.g., Internet addiction as a result of social construction). It is noteworthy that few theories have explicitly addressed Internet addiction, although Internet addiction can be understood in terms of their related theoretical propositions. Finally, health professionals should understand the strengths and limitations of different theories of Internet addiction and the assumptions of man intrinsic to different theories.

Biological Perspective

From the biological perspective, Internet addiction, as with other mental disorders, can be understood through a medical model, in which biological mechanisms are believed to be the major cause of the problem and psychotropic drugs are considered useful in treating Internet addicts. Research has shown that some genes are related to the general risk of addictive behavior whereas some are related to the vulnerability (or invulnerability) of individuals to develop a specific addiction. Moreover, different types of gene are involved in different stages under various mechanisms in order for the addictive behavior to occur. Hence, rather than investigating a single behavioral gene, many genes are identified at the same time in order to find the genetic cause of addiction. Empirical studies in genetics and neurobiology have provided support for the biological understanding of Internet addiction. In a recent study, genetic polymorphisms of the serotonin transporter gene (SS-5HTTLPR) have been identified in Internet addicts. Given that this polymorphism is associated with other psychiatric problems, such as mood disorder and anxiety disorder, as well as other substance addictions, further replications are needed for validation. Using voxel-based morphometrical technique, some researchers reported that adolescent Internet addicts had lower gray matter density in the left anterior cingulated cortex, left posterior cingulated cortex, left insula, and left lingual gyrus, as compared with healthy controls. This finding suggests individuals who are addicted to the Internet may have deficits in decision-making function and strategy learning lag. With the development of more advanced neuroscience and genetic techniques, it can be foreseen that new insights into the etiology of Internet addiction will emerge.

Other biological theorists attempt to link addictive behaviors with excessive secretion of a neurotransmitter such as dopamine. Neurological studies have shown that both drug and addictive behaviors (e.g., gambling) could elevate dopamine levels and cause a feeling of euphoria in the addicts. Excessive Internet use may affect this neurotransmitter system of the brain in much the same way as other addictive substance and behaviors. However, there is evidence showing that an increased level of dopamine can cause addictive-like behaviors. It has also been suggested that Internet addictive behavior and the secretion of dopamine may mutually reinforce one another, whereby the addicts can continuously enjoy the pleasure by excessively browsing the Internet. Therefore, the cause-and-effect relationship between excessive dopamine secretion and Internet addiction has yet to be established. Besides, such medical-model-based addiction studies are mostly conducted in the area of substance addiction while limited research attempt to address behavioral addiction such as Internet addiction. Hence, empirical support for the biological theory of Internet addiction is still at its infancy.

Biological explanations of Internet addiction appears to be scientific and objective with wide applications in the medical field. Nevertheless, there are several questions that need to be considered. First, the notion of biological determinism neglects the role of other psychosocial factors in the development of Internet addiction, such as one's personality, family relationship, peer influence, as well as the sociocultural environment. Second, genes generally act probabilistically rather than deterministically, and genetic factors are always associated with environmental factors. It has been claimed that inherited predispositions plus adverse environmental conditions trigger mental disorders, as described in the diathesis-stress model. Some authors further propose that nongenetic/environmental factors are likely to trigger the genetic risk and cause addictive behaviors. As it is difficult to identify their effects on addictive behaviors separately, simply using a biological model to understand Internet addiction is apparently insufficient. Finally, while medical treatment based on the biological theory can remove some addictive symptoms temporarily, its long-term effects tend to be poor when psychosocial factors are not taken into account, and prolonged drug taking may also lead to other problems.

Psychoanalytic Perspective

Originally developed by Sigmund Freud, psychoanalysis has a long history and can be regarded as the first theory on personality, psychopathology, and psychotherapy. In contrast to the rational image of men since the Enlightenment era, Freud's emphasis on the irrationality of human behavior constitutes a radical change in the view of human nature.

According to classic psychoanalytic theory, all abnormal behaviors are unconsciously caused, which involves unresolved intrapsychic conflicts existing among various personality structures (i.e., the "id," "ego," and "superego"). In Freud's famous structural model of the psyche, the human mind can be divided into three theoretical constructs in terms of whose activities and interaction mental life is described: the irrational and impulsive id (a representation of primal animal desires), the judgmental superego (a representation of society inside the mind), and the rational ego (which functions as a bridge between id and superego, attempting to coordinate the two parts). According to this model, Internet addiction can be seen as the result of an over-strong id (which seeks pleasure and gratification via Internet activities), a weak superego (which has low ego ideal and conscience), and a weak ego (which cannot rationally mediate the demands of the id and the constraints of the superego).

The concept of psychosexual development is another key element of Freudian theory, which posits that humans have instinctual libidinal drives from birth which unfold in a series of stages: oral, anal, phallic, latency, and genital. Overinvestment or underinvestment of psychic energy on a specific psychosexual developmental stage during childhood would lead to the fixation at that stage and result in different adulthood psychopathology. The emergence of addiction is deemed as the result of fixation at the anal stage and the representation of the anal expulsive character, such as being disorganized and defiant and lack of self-control. This explains why Internet addicts have poor skills on time management and unable to control themselves from excessive Internet use.

In the neo-Freudian perspectives (e.g., Erik Erikson, Carl Jung, Sullivan), changing foci on human rationality, interpersonal relationships, family, and psychosocial environment are presented, based on which different psychopathological theories are stipulated. According to different psychoanalysts, addictive behaviors are seen as a result of identity crisis, lack of love, family dynamics, and weakness in the formation of the "self." One contemporary psychoanalytic view considers addiction as a defense against anxiety. Addicts are indulged in a particular behavior or substance to protect themselves against overwhelming anxiety and other painful experiences (e.g., trauma) and feelings such as depression and loneliness. A common acronym, "H-A-L-T" meaning hungry, angry, lonely, and tired, is often used to represent for the four emotions that lead to vulnerability and subsequent addictive behaviors. Therefore, the Internet is used by its addicts as a way to dampen anxiety and avoid any potentially threatening situations such as various personal, familial, and social activities.

Sullivan's interpersonal theory is another influential psychoanalytic theory that is often used to further understand Internet addiction. This theory states that people can never be disengaged from the complex of interpersonal relations in which they live and have their own being. Frustrated or unpleasant interpersonal relationship during childhood results in the rise of social anxiety. For people with high social anxiety, the Internet may well fulfill their social needs, add their social connectedness, and provide them a sense of belonging. These people are most likely to become Internet addicts.

While psychoanalytic theory focuses on the importance of the unconsciousness and childhood experience that is largely neglected in other theories, there are several criticisms upon this perspective. The first criticism is that concepts in psychoanalytic theory are hard to operationalize, which makes verification difficult if not impossible. Second, there is the problem of unfalsifiability because childhood trauma/experience as an explanation can be always true. Third, psychoanalytic theories are basically developed on abnormal samples, thus raising the question of whether it is possible to generalize the findings to normal populations.

Behavioral Perspective, Cognitive Perspective, and Cognitive-Behavioral Perspective

As one of the dominant schools of thoughts in psychology, behavioral theories state that environmental events determine human behavior through the process of learning. Learning theory with its foci on classic conditioning and operant conditioning is commonly used to explain the development of addictive behavior. Classical conditioning is a form of associative learning, i.e., when a conditioned stimulus and an unconditioned stimulus are repeatedly paired, the two stimuli would eventually become associated and the conditioned stimulus would elicit the unconditioned response. In the case of Internet addiction, it is believed that Internet use behavior may be repeatedly paired up with some emotional experiences and/or environmental cues and thus formulate an association with these factors. As such, while individuals are exposed in similar environment and experiences that are associated with Internet use, they may automatically/unconsciously wish to use the Internet. Operant conditioning refers to the principle that consequences of a behavior influence the likelihood of that behavior being repeated. Surfing on the Internet may produce a variety of desirable consequences including approval, relaxed feeling, tension reduction, avoidance of withdrawal symptoms, and disappearance of negative emotions. Under this principle, all these desirable consequences may positively reinforce the Internet use behavior and eventually lead to Internet addiction.

In contrast to behavioral theory's emphasis on simple associative learning, cognitive theories are based on the assumption that humans are logical beings who make the choices that make the most sense to them. Cognitive theorists attempt to explain human behavior by understanding the thought processes and focus on the importance of the active role of the perceiver and mental transformation of sensory information. To the extent that one's thinking processes (including beliefs, attitudes, perceptions, and interpretations) are faulty and biased, one's emotional and behavioral responses to different life events will be problematic, which leads to different psychological problems including Internet addiction.

There are two general versions of cognitive theories. In those models adopting a more mechanistic view (i.e., man is likened to a computer or thinking machine), errors in information processing lead to abnormal behavior. According to this view, biases in individuals' perceptions and memory processes associated with Internet use are the causes of Internet addiction. Internet addicts tend to pay greater attention to or selectively remember some Internet-use-related information than others. For example, while an Internet addict may experience both positive and negative outcomes caused by Internet use, he/she chooses to remember the positive experiences rather than those negative ones. Another school of cognitive theories view psychological disorders as the results of problems in people's active thinking processes, such as understanding, interpretation, evaluation, and prediction. It has been found that Internet addicts usually expect Internet use behavior to be a way of demonstrating one's power and have the effects of obtaining social approval. Based on an initial cognitive model of depression postulated by Beck, researchers have proposed a similar cognitive model of addiction. In this model, it is believed that repeatedly replaying (ruminating) the cognitive distortion of stressors creates unpleasant thoughts and that addictive behaviors serve as a coping strategy for the individual to escape from these unpleasant experiences. In other words, Internet addictive behavior, like a distraction, allows the individual to turn off the unpleasant thoughts of rumination about their stressors. Such a maladaptive strategy prevents the individual from facing and dealing with their real problems in a healthy manner and often produces more problems. Thus, to treat people who are addicted to the Internet, their cognitive distortions must be corrected and rumination needs to be stopped.

While behavioral theories are reprimanded for solely emphasizing the importance of environmental factors but ignoring the role of the human being's cognitive ability, cognitive theories, to the contrary, are criticized as overstressing the importance of rationality and conscious thinking process in the formation of Internet addictive behaviors. In response to these criticisms, researchers have attempted to integrate both cognitive and behavioral factors in explaining the etiology of Internet addiction. As a result, different cognitive-behavioral models have been proposed.

Among various cognitive-behavioral models, one leading theory about Internet addiction is the cognitive-behavioral theory of pathological Internet use proposed by Richard A. Davis. This model argues that certain cognitive symptoms may come before or cause behavioral symptoms. Davis believes that there are two distinct forms of pathological Internet use: specific and generalized, with only the generalized pathological Internet use can be regarded as the real case of Internet addiction. According to Davis, specific pathological Internet use is defined as content specific. Individuals demonstrating this pattern of use are in fact dependent upon a particular function of the Internet, for example, online shopping, pornography, and online gambling. In such cases, the Internet is merely a tool for exhibiting maladaptive behaviors that would also be exhibited without Internet. In contrast, generalized pathological Internet use is characterized by overuse of Internet for multiple purposes. This is considered the genuine and more problematic form of the disorder and is assumed to be related to the more social characteristics of the Internet. Under this cognitive-behavioral theory, both specific and generalized pathological Internet uses are explained as a result of distal and proximal contributory causes. The nature of distal contributory causes is explained in this theory by the diathesis-stress model of abnormal behavior. For Internet addiction, the diathesis is represented by pre-existing or underlying psychopathology which may not directly cause excessive Internet use but serves as a necessary factor to its development. The stress in the model is one's exposure to the Internet. When the individual receives reinforcement from an experience with the Internet, the process of operant conditioning begins and the individual becomes vulnerable to secondary reinforcers (e.g., the sound of typing). These secondary reinforcers may contribute to the development of Internet addiction symptoms, which then are maintained or further strengthened by the proximal contributory causes. Proximal contributory causes are represented by specific maladaptive cognitions such as rumination, i.e., constantly thinking about problems associated with one's Internet use, as well as negative self-appraisal.

There are other cognitive-behavioral perspectives that can be used to explain Internet addiction. It has been proposed that Internet addiction is caused by accessibility to Internet and beliefs associated with its use. When individuals can access the Internet whenever and wherever they want, it increases the probability of them becoming Internet addicted (i.e., external reinforcement). Similar to Davis' model, some theories emphasize that psychosocial problems such as depression and loneliness predispose Internet users to develop maladaptive cognitions, such as Internet surfing can solve their problems. For example, Internet addicts may be aware of the damaging effects brought by excessive Internet use, but they will do anything to "feed their addiction." According to the social-learning theory postulated by Bandura, low self-efficacy (i.e., the belief that one has abilities to control or make something happens) and poor coping strategies elicit the risk of developing addictions to cope. Cognitive-behaviorists also suggest that disruption in the areas of identity formation and developing meaningful relationships or intimacy may lead the individual to use the Internet as a means of escape and emotional numbing or fulfilling developmental intimacy needs. Besides, there is research evidence showing that self-efficacy, modeling effects, and outcome expectancies (i.e., believing that the Internet brings certain rewards) are related to Internet addictive behavior. To date, Davis' etiology model of pathological Internet use is considered the most encompassing theory of Internet addiction using the cognitive-behavioral approach.

Humanistic Perspective

Representing another force in psychology, humanistic theory distinguishes itself from other psychological approaches by focusing on subjective meaning, rejection of determinism, and concern for positive growth rather than pathology. Humanists, representatively by Abraham Maslow and Carl Rogers, advocate a positive view of man's inner nature with the emphasis on man's creative potentials, subjective experiences, and feelings.

Based on Abraham Maslow's hierarchy of needs theory, Internet addictive behavior can be explained as an attempt to satisfy one's interpersonal needs, self-esteem needs, and self-actualization needs in a virtual world when the individuals fail to meet these higher-ordered needs in reality. In other words, failures on fulfilling one's love and belongingness needs in reality can cause Internet addiction because the Internet provides a more comfortable and safer place for the individual to fulfill these needs. In terms of Carl Rogers' humanistic theory, addictive behavior may exist as a way to enhance one's low self-worth and self-regards resulting from the lack of unconditional positive regard from others and oneself. The Internet acts as an alternative for individuals who have difficulties in expressing real self in a traditional world that allows them to deal with problems on self-expression which may not be essentially bad.

In the flow theory, "flow" is defined as a mental state in which individuals are so involved in an activity that nothing seems to matter. Flow theory is assimilated by humanistic theorists who focus on the intrinsic motivation and interest behind an action such as Internet addiction. Under this view, Internet addicts are seen as being in a "flow" because nothing seems to matter when they are involved in online activities. The flow state is intrinsically rewarding and enjoyable that individuals will seek for replicated experiences. Individuals are willing to sacrifice in order to gain the happiness experiences during Internet use.

Closely related to the humanistic perspective is the existential perspective which maintains that problems in human existence such as lack of meaning of life, inauthentic life, alienation, and inadequacies of human nature contribute to addictive behavior. Existentialists propose that all kinds of addiction are rooted in meaninglessness, fear of alienation, and loss of freedom. Using the notion of "existential vacuum" proposed by Viktor Frankl, it is proposed that whenever an individual lacks meaning in life, psychopathologies including Internet addiction will rush in to fill it. Also, existential theorists believe that unauthentic life may lead to life anxieties which may further lead to Internet addiction.

Although humanistic approach is widely applied in clinical settings and its emphasis on the positive attributes of human beings is endorsed by many health professionals, scientific studies on the humanistic perspective in the context of addiction are sparse. However, from a psychotherapeutic point of view, humanistic principles of acceptance and empathy are important in understanding the subjective experiences of Internet addicts.

Interpersonal and Family Perspectives

Besides theories which attempt to explain addiction in terms of intrapersonal mechanisms, there are theories focusing on the interpersonal factors in the Internet. From the interpersonal perspective, abnormal behavior is seen as a reflection of the problem in the interpersonal systems.

As reviewed in previous sessions, Harry Stack Sullivan's interpersonal psychoanalysis is the foundation of many interpersonal theories. According to Sullivan, interpersonal factors are important in one's life, notably peers and parent-child relationships. Parent-child relationship as a primary experience of a child shapes the formation of one's self-image and has significant effects on the child's later social relationships. With the awareness of alienation rising during adolescence, interpersonal sensitivity and conflicts among peers are taken very seriously by young people. It is believed that interpersonal factors especially peer relationship have particularly important effects on adolescents' development. There are many studies showing that undesirable peer influence leads to addictive behavior. Through peer influence, norms and expectations about "acceptance" of Internet use are defined. Peer influence also provides incentive through social approval of Internet-related behavior.

Family structures and processes are believed to be another determinant of human behavior. Family theorists propose that different systemic family functioning processes, such as communication, emotional expression, and conflicts, are related to addictive behavior. Different dyadic processes are also related to addictive behavior in adolescents. These dyadic family processes include parental marital problems, improper parenting such as loose parenting, prolonged parent-child conflicts, and problematic parent-child relationship. According to family systems perspective, habitual behavior within relationships such as parental overcontrol or over-detachment leads to adolescent developmental problems. In structural family therapy models, such as the one developed by Salvador Minuchin, intergenerational conflict can lead to Internet addiction problem in adolescents. In terms of treatment, multidimensional family intervention programs are developed to treat clients with Internet addiction problem.

There are views suggesting that family history of having addiction can offer modeling and facilitate addiction belief systems of individuals. Besides, conflicts with family can create an atmosphere where Internet use will be used as a means for individuals to escape from family tension (i.e., negative reinforcement). According to Sullivan's interpersonal theory, adolescents who had poor relationships with parents will later develop poor social skills and social relationships. Adolescents will choose to spend excessive time on the Internet in order to escape from real social interaction and conflicts with families. In addition, family cohesion and increased parental involvement can serve as protective factors for addictive behavior. Of course, one should be aware of the possibility that increased family interaction may lead to a higher possibility of parent-child and family conflicts.

Sociocultural Perspective

In the sociocultural perspective, several explanations for Internet addiction have been proposed. First, Internet addiction can be seen as a reflection of social pathology such as social alienation, social stress, and inequality where people cope with social stress and inequality through addiction. Second, it is suggested that different social factors, such as religiosity, subcultures, and social class, are related to addictive behavior. Finally, according to social constructionist thoughts, Internet addiction is a concept constructed by scientists which may not exist in the reality.

Different theories have their respective foci while explaining Internet addiction, ranging from micro reductionist focus in the biological perspective (e.g., genetic emphasis) to macro holistic focus in the sociocultural perspective. Empirical research also provides varying extent of support for the validity of different theoretical accounts. Generally speaking, there is less support for humanistic and psychoanalytic perspectives than for cognitive and behavioral theories. Furthermore, the degree of application of these theories in treatment tends to be different. Finally, there are distinct assumptions of human existence associated with theories of Internet addiction. For example, human beings are seen as determined (unconscious determinism) and irrational under the psychoanalytic perspective while they are seen as free and rational under the humanistic perspective.

Ecological Perspective

How can theoretical perspectives with different emphases be integrated? In the past few decades, there is a growing awareness of adopting an ecological perspective to understand and treat Internet addiction. In the ecological perspective, it is proposed that risk factors in different systems, including the individual level (e.g., high sensation seeking, meaninglessness), family level (e.g., growing up in non-intact families), school level (e.g., low academic achievement, poor peer relationships), and community level (e.g., growing up in deprived communities), increase the chance of Internet addiction. On the other hand, it is also proposed that protective factors in different systems, including personal level (e.g., healthy attribution style, self-efficacy, hope, faith, and optimism), interpersonal level (e.g., supportive home environment and parental guidance), and community level (e.g., good schools, community assets, and other external support systems), will reduce the probability of Internet addiction in young people. Historically, the utilization of risk and protective factors has shaped the "prevention science" perspective. Based on this perspective, developers of positive youth development programs attempt to reduce the impact of risk factors but promote the influence of protective factors via the developed programs.

One example of such an integrative and ecological model is the addiction syndrome model proposed by Shaffer and colleagues. According to this model, there are factors in different systems which are common to different forms of addiction. These include biological predisposition (such as genetic influences and neural mechanisms like excessive dopamine level), personality traits, and environmental opportunities such as families with addictive behavior.

To be more specific, in the addiction syndrome model, addiction is understood as a syndrome with multiple opportunistic expressions, i.e., various forms of substance addiction (e.g., alcohol, cigarette, or marijuana) and behavioral addiction (e.g., gambling, Internet use, or pathological shopping). Each outwardly unique addiction disorder is a distinctive expression of the same underlying addiction syndrome. Not all types of addiction disorders are present in every expression of the syndrome, and some manifestations of the addiction syndrome have unique signs and symptoms, which serve as the identifying characteristics of the underlying condition and may have their respective temporal progression. Different addictive disorders share some common neurobiological antecedents (e.g., genetic risk, neurobiological system risk), common psychosocial antecedents (e.g., psychological and social risk factors), and common experiences. These commonalities reflect their shared etiology.

In terms of the addiction syndrome model, people encounter and accumulate specific combinations of neurobiological and psychosocial elements that can influence their behavior throughout the course of developing addiction. Exposure and access to an object of addiction increase an individual's likelihood of interacting with that object, which in turn can expose at-risk individuals to neurobiological consequences that are both common to all objects of addiction and unique to specific objects of addiction. When individuals engage in repeated interactions with a specific object or objects of addiction, and the neurobiological or social consequences of these interactions produce a desirable subjective shift that is reliable and robust, the premorbid stage of the addiction syndrome emerges. During this stage, people are like standing on a seesaw that may shift them toward either more or less healthy behavior, determined by different risk or protective factors. Some risk biopsychosocial factors (e.g., genetic factor, poor social support) would influence the process and lead to further development of the addiction syndrome. Dependent upon the object with which people interact, the addiction syndrome can manifest itself in different ways (i.e., expression of different addictive disorders). More importantly, the addiction syndrome can be recursive, and its sequelae can generate an entirely new vulnerability profile, for example, provoke reward-system malfunction in a previously normal system. Therefore, the development of the addiction syndrome places people with the syndrome at increased risk for continuing addictive behavior and for developing new addictive behaviors.

The addiction syndrome model presents researchers and clinicians a new way to rethink Internet addiction and holds important implications for both research and practice. As suggested by Shaffer et al. (2004), the syndromal view of addiction advances an improved understanding of both proximal and distal influences of different addiction disorders, promotes the development of an etiologically based diagnostic criterion, and encourages the utilization of pharmacological and psychological non-object-specific treatments for addiction.

Psychosocial Correlates

In view of the growing Internet addiction problem in adolescents, one obvious question is how Internet addiction in adolescents could be prevented. From the prevention science perspective, there are two approaches dominating the development of preventive strategies. The first approach adopts the "traditional" conception which includes three levels of strategies dealing with the problem: (1) primary prevention (the elimination of the occurrence of problems), (2) secondary prevention (the early identification of high-risk groups and early intervention), and (3) tertiary prevention (the prevention of further deterioration of the problem). The second approach adopts the "changing" conception which includes three target groups: (1) universal prevention (targeting all adolescents regardless of their risk status), (2) selective prevention (targeting adolescents who have above-average risk of behaviors but there is no indication that their participation in risky behaviors is a problem), and (3) indicated prevention (targeting adolescents with noticeable signs and markers of a behavioral problem even they are not diagnosable). The focus on primary prevention and universal prevention initiatives have been commonly used to prevent adolescents' risky behaviors such as substance abuse and Internet addiction.

According to the ecological perspective, a popular strategy used in adolescent prevention programs is to identify the risk and protective factors in the development of problem behavior. The purposes are to minimize the risk factors and to maximize the protective factors in young people. This strategy could be very useful in preventing Internet addiction because reducing the risk factors involved in Internet addiction and strengthening its protective factors can work simultaneously and reinforce the effects of each other. Hence, it is important to examine the psychosocial correlates of Internet addictive behavior with reference to different ecological systems.

To begin with, research findings have shown that Internet addiction is related to a few demographic factors. First, gender is correlated with Internet addiction. A common finding is that there are significantly more males than females who are identified as Internet addicts, although the number of females involving in excessive Internet use is increasing. This is in accordance with literature on other addictive behaviors. However, this finding may simply be due to the fact that more males than females use the Internet across the world. Second, age has been consistently reported as an important factor relevant to Internet addiction. Individuals who are in the developmental stages such as adolescence and young adulthood are more likely to become Internet addicts, as compared to other age groups. Some researchers explain that adolescents who are in the process of psychological development and solidifying their personality may be particularly vulnerable to developing addictive behaviors. Researchers have also pointed out some other risk factors specific to this age group, including a strong desire to develop a sense of identity, a need to build up intimate relationship, and easily having access to the Internet either at home or in school. As the behaviors shaped in adolescence are likely to develop into lifetime patterns, it is particularly important to prevent such problems in this population. Third, occupation is found to be another predictor of Internet addiction. White-collar workers are more likely to become addicted to Internet than are blue-collar workers. This may be explained by the higher salary and time for wider access to the Internet in white-collar workers than in blue-collar workers. The nature of different jobs also requires different amount of time spent on the Internet, which inevitably influence the likelihood of developing Internet addiction.

Next, at family and interpersonal level, several factors have been identified as either protecting against or increasing the likelihood of developing Internet addiction among adolescents. As far as family protective factors are concerned, family monitoring, family cohesion, and positive parenting attitudes are negatively related to Internet addiction. Some studies show that participative and supportive parental monitoring can help to protect adolescents from becoming Internet addicts. Good parent-child relationship is another protective factor which is positively related to the child's interpersonal relationship while negatively related to Internet addiction. In fact, the quality of interpersonal relationship is another predictor of Internet addiction. Research suggests that poor quality of interpersonal relationships exposes adolescents to an increased risk of developing Internet addiction. In addition, lack of interpersonal skills is often associated with adolescents' overdependence on Internet use. These adolescents are unable to make friends in real life, so they spend much time on the Internet to compensate for the satisfaction that cannot be fulfilled in reality. Other risk factors for Internet addiction include negative parental rearing style, family violence, parental marital discords, family dissatisfaction, and substance abuse of family members. It has been reported that Internet addiction is more prevalent among adolescents who grow up in single-parent families, have high parent-adolescent conflict, have high interparental conflict, live with family members with alcohol abuse, and have overprotective parents. It should be noted that in one study, conversation time with family members had no effect on Internet addictive behaviors, which may suggest that the quality of interfamily communication is more important than the time spent.

Finally, on the individual level, several personal factors are found to be related to Internet addiction. Personality characteristics that have most frequently been associated with Internet addiction include shyness, low self-esteem, lack of social and emotional skills, and lack of locus of control. Shyness refers to the apprehension to meet people and the distress associated with the presence of others, which is closely related to the anxiety about negative evaluation by others. Compared with those who are not shy, shy individuals usually have poor interpersonal relationships and social support. As a result, they are much more likely to gain social comfort via alternative ways, and the Internet is an attractive alternative. Low self-esteem and lack of emotional and social skills are the same factors that put individuals at high risk for other psychological problems such as depression. Researchers have suggested that the Internet may provide individuals a safe place to decrease a perceived deficit in their real social interaction because of its anonymity and lack of face-to-face interaction. Locus of control means whether one believes that one's life is controlled by themselves or events beyond their control. Those who think they have no control of their real lives (i.e., external locus of control) may turn to Internet in order to gain control.

There are consistent empirical findings suggesting that Internet addiction occurs with other psychopathology, such as depression, anxiety, attention deficit hyperactivity disorder (ADHD), substance use, and other addictive behavior. It was found that Internet addicts have higher neuroticism, psychoticism, emotional symptoms, hyperactivity, and conduct problem but lower level of pro-social behavior, as compared to non-Internet addicts. One specific study in the area reported that all 20 individuals diagnosed as having Internet addiction also had at least one DSM-IV Axis I diagnosis (Shapira et al. 2000). In another study, nearly 50% of participants reporting excessive Internet use met the diagnostic criteria for a psychological disorder, with the most commonly reported disorders being substance use, mood disorder, and anxiety disorder. However, the causal pathway between Internet addiction and psychopathology is uncertain. It is difficult to determine whether these psychological problems/disorders promote the development of Internet addiction or are caused or accentuated by excessive Internet use.

Research findings also support the associations between time management skills, coping style, risk-taking behaviors, and Internet addiction. Studies have revealed that adolescents who are addicted to the Internet tend to adopt negative coping styles such as fantasy or retreat, instead of problem solving or rational approaches. Time management skill is another correlate of Internet addiction, with those who have poor time management skills being more likely to overuse the Internet. Moreover, risk-taking behavior appears to be related to Internet addiction as well. One study in Taiwan shows that Internet addicts score higher on novelty seeking and harm avoidance and lower on reward dependence compared to nonaddicts. Novelty seeking is the strongest predictor of Internet addiction among these factors. Similarly, it has been reported that Internet addiction is positively related to boredom susceptibility and sensation seeking but negatively related to participation in other leisure activities. For some researchers, boredom avoidance is the main motivation for adolescents to use the Internet. In addition, stressful events such as academic pressures and workloads have been identified as a key factor triggering Internet addiction.

Several points should be noted when examining the psychosocial correlates of Internet addiction. First, probably because of conceptual and methodological differences, findings on the psychosocial correlates of Internet addiction (such as gender and depression) are not strictly consistent. As such, replications and studies with different sample characteristics should be carried out. Second, there are different possible interpretations about the relationship between Internet addiction and other psychopathological symptoms. Taking depression as an example, depression may lead to the development of Internet addiction while it is also possible that excessive Internet use causes depressive symptoms, or depression and Internet addiction mutually influence each other. Another possibility may be that the relationship between depression and Internet addiction is due to a third variable (i.e., spurious correlation), for example, genetic vulnerability to psychopathology. Ideally, longitudinal designs should be used to test the above possibilities. However, longitudinal studies utilizing multiple indicators are almost nonexistent in this area, and even if such studies are available, the sample sizes are usually small. This gap points to the direction for future research.

Treatment of Internet Addiction

Similar to other forms of addiction, treatment and recovery of people with Internet addiction go through several stages. Prochaska and DiClemente proposed that there are several phases in the process of change, including pre-contemplation, contemplation, determination, action, maintenance, and relapse. In the pre-contemplation stage, the person may not think that his/her Internet use behavior is problematic and he/she does not consider changing his/her Internet use behavior. In the contemplation stage, the person starts to realize that his/her Internet use behavior is problematic and considers the possibility of changing. However, the consideration is ambivalent in nature. In the determination stage, the person decides to change his/her Internet use behavior. In the action stage, the person starts to decrease his/her online time. The person is successful in changing if he/she can maintain the changed Internet use behavior. Otherwise, relapse occurs and he/she might go through the stages of change again. This model has been widely used by therapists to understand the process of change in people with addiction and develop corresponding treatment strategies.

Broadly speaking, intervention for addictive behavior can take place at different levels, including individual intervention (i.e., changing the individual behavior), family intervention (changing the family antecedents of Internet addiction), interpersonal intervention (changing the peers who influence one's addictive behavior), and other forms of intervention such as changing legislations and policies.

For individual intervention programs, several approaches have been adopted to treat Internet addiction. First, medical intervention can be used to treat Internet addicts especially those with comorbid psychological conditions, including mood disorders, anxiety, substance abuse, pathological gambling, ADHD, and other problems. In medical settings, psychiatrists may prescribe medicine for these patients. Antidepressant drugs like selective serotonin reuptake inhibitors (SSRIs), such as fluvoxamine (Luvox), fluoxetine (Prozac), and sertraline (Zoloft), and nonaddictive antianxiety medicine are commonly used to treat corresponding symptoms. Some patients even need antipsychotic medication occasionally. Such treatment helps patients to concentrate and enter into more productive therapy. However, medication cannot by itself cure Internet addiction and is frequently used in conjunction with individual, group, and family psychotherapies.

Compared to medical treatment, various forms of psychotherapy have been more widely used as intervention strategies for Internet addiction. Based on the psychoanalytic perspective, psychoanalytic treatment of Internet addiction generally does not focus on symptoms (i.e., the addictive behavior) but on the underlying cause, or the core conflict. Therapeutic attempts are thus made to make the unconscious become conscious through different psychoanalytic techniques including free association (surface of the repressed and latent thoughts), interpretation (deduction, awareness of resistance), transference (development of emotional bondage), abreaction or "catharsis" (emotional cleansing), insights (understanding the root of the problem and reeducation), working through, and ego strengthening. The central focus is the addictive behavior in association with the core conflict, which is always conceptualized and interpreted within an interpersonal framework. The psychodynamic-oriented therapists view Internet addiction as a form of dissociation in which individuals retreat from the painful experience in the real world to a subjective state where they can control and capture things they need. As such, psychodynamic-oriented treatment focuses on co-constructing with the patients a transitional reality in which the patients can restore their trust in real human relatedness. The therapists may explore the addictive behavior but also seek to disengage it from the underlying self-state which is believed to be essential for the patients' psychic survival. The therapeutic aim is to search for the relational bind embedded in the Internet use, formulate it as a conflict in symbolic terms, and explore it within the new relationship developed in the transference. However, although different psychoanalytic perspectives greatly deepen the understanding of Internet addiction, such insight-oriented psychotherapies generally have a poor success rate in treating addictive patients. Sound empirical evidence that supports the effectiveness of psychoanalysis in treating Internet addiction is scant.

Behavioral approach based on operant conditioning principles is based on the premise that a certain behavior (like an addiction) starts by rewarding this behavior (positive feedback) and is reduced by punishment (negative feedback). Therefore, behavioral therapy uses rewards and punishments to achieve positive behavior and to reduce negative behavior. A radical way to cure Internet addiction as suggested by some hard-line behavioral therapists is to stop using the Internet. This so-called "all or nothing" treatment plan may be unpractical because computer usage in the society is so pervasive that total abstinence of Internet use is impossible. As an alternative, researchers have proposed that Internet addiction should be treated like an eating disorder where the goal is to normalize network use. The techniques focus on helping Internet addicts change the way they live their lives so that they can successfully reduce their Internet use and develop healthy and productive lives. Therapists teach their addicted patients about Internet addiction, encourage them to make changes in their lives, praise them when they make progress, and support them when they run into problems. There are several treatment strategies based on the principle of behavioral therapy: (a) improve motivation for recovery: help individuals recognize the damage that Internet use is doing to one's life, encourage them to stop use, and support positive steps toward recovery; (b) teach skills for stopping Internet use and avoiding relapse; (c) use positive incentives to encourage treatment participation and reward progress; (d) involve family members in treatment activities and ask them to provide appropriate help and support in the recovery process; and (e) encourage participation in recovery support groups.

Cognitive-behavior therapy (CBT) is developed upon the assumption that thoughts determine feelings and behaviors, which has been shown as an effective treatment for both substance addiction and behavioral addiction. When using CBT to treat Internet addiction, patients are taught to monitor their thoughts and identify the points that trigger addictive feelings and actions. Meanwhile, patients also learn new coping skills and ways to prevent a relapse. CBT usually requires 3 weeks or approximately 12 weekly sessions. In the early stage of treatment, the focus is on specific behaviors or situations in which impulsive behaviors cause the greatest difficulty. As therapy progresses, there are more foci that are placed on the cognitive assumptions and distortions that the patients have developed and their effects on behavior. This treatment typically involves assessment of the type of distortion, problem-solving skills, and coping strategies training, modeling in therapy, support groups, and keeping thought journals. Research findings provide evidence supporting the effectiveness of CBT in decreasing addicts' Internet use and improving their time management skills and emotional, cognitive, and behavioral symptoms.

Grounded in the humanistic approach, motivational interviewing (or motivational enhancement therapy) is another commonly used therapeutic model in treating Internet addiction. Motivational interviewing is a directive, client-centered counseling style for eliciting behavior change by helping clients to explore and resolve ambivalence. It assumes that the responsibility and capability for change are within the client. Five basic principles are intrinsic to motivational interviewing. These include (a) expression of empathy via reflective listening to convey understanding of the client's thinking and feeling, (b) pointing out discrepancy between the client's current behavior and future goals, (c) avoiding unnecessary arguments which evoke resistance to change, (d) viewing resistance and ambivalence as normal and exploring them openly, and (e) supporting self-efficacy by building the client's confidence that he/she can make a change. There are research findings supporting the effectiveness of motivational interviewing in the context of treating different addictive behaviors.

Several motivational interviewing techniques are frequently used by counselors in helping Internet addicts. The first technique is the elicitation of self-motivational statements including the clients' talk of concerns about online behavior, desire, reasons, ability, and commitment for change. Such statements should be elicited from the clients rather than being told or imposed. The second technique concerns how resistance is handled. The therapist usually does not enter into arguments about the client's beliefs, perceptions, and behaviors which may produce more resistance. Rather, the therapist acts as a collaborator aligned on the side of the individual to solve the problem. If the clients exhibit resistance through behaviors like anger, inattention, or interruption, the therapists must change the approach and help to decrease defensiveness and hostility of the clients through reflective listening and similar techniques. In the process, the therapist also emphasizes that the client has the responsibility to choose whether they want to change. The third technique focuses on the "good things" and "less good things," with "good things" about online being explored together with the adolescent clients, followed by the "less good things" about online. This strategy is important because adolescent clients tend to be more willing to discuss the "less good things" after the "good things." The fourth technique is decisional balance. The discussion is similar to "good things and less good things" except it focuses on future behavior. The pros and cons of changing the Internet addictive behavior are then identified and compared with the pros and cons of not changing the behavior. The emphasis is on the spirit that adolescent clients can make differences and they can choose to live in the way they really want. The fifth technique is values exploration where clients are encouraged to rank different value statements. The meaning of value statements, discrepancies between values and their current online behavior, and perceived barriers and opportunities of decreasing discrepancies are then discussed. Counselors could ask the clients about their short-term and long-term goals and how Internet addiction may hinder their goal achievement. This process helps the adolescent clients to evaluate whether their behavior fulfills short-term needs while violating the values they treasure in the long run. The next technique is discussion of the stages of change. The stages of change are explained, and the adolescent clients are asked to determine their current stage. The adolescent clients are also helped to review whether they experience different stages of change in the past and what would cause them moving between different stages. Other basic techniques of motivational interviewing summarized by the acronym OARS (open-ended questions, affirmations, reflective listening, and summarization) are also applied.

Besides motivational interviewing therapy, other individual counseling techniques are commonly used. The first is feedback on online behavior where objective assessment on Internet addiction is conducted and the results are discussed. The second technique is construction of personal inventory. A list of activities that have been neglected after the adolescent clients' onset of Internet addictive behavior is constructed. This technique helps the adolescent clients to evaluate the negative impacts of stopping doing the interesting or important activities due to the Internet addiction behavior. Third, construction of behavioral contract, including set time limit on using Internet and exploration of alternatives which can fill the free time after spending less time online, and difficulties of implementation and the related solutions are discussed. Finally, development of career plan and related action plan such as taking courses or applying jobs are discussed with the client. This aspect is essential for those who have left school and are unemployed as they have a lot of free time to stay online if the nonengaged situation persisted.

With particular reference to the change model, it is believed that different counseling tasks should be fulfilled at different stages. In the pre-contemplation stage, the counseling tasks include making connection by expressing empathy; understanding the daily functioning, thinking, and feeling with respect to different areas such as school, peer, and family contexts; understanding the needs and concerns of the client; understanding the positive and negative aspects of Internet use; and developing discrepancy between what one wants and the current Internet use behavior. In the contemplation stage, the counseling tasks consist of constructing decisional balance about change and not change, which is in favor of changing current Internet use behavior; strengthening self-efficacy so as to enhance the possibility of change is also a focus. In the determination stage, counselors shall attempt to help the clients to develop plans for changing Internet use behavior (not just an Internet use time table) as well as study or career plans. Different resources might be introduced whenever appropriate. Also, engaging the client to join peer support group, interest class, or voluntary services is important. In the action stage, the counseling tasks are strengthening the problem-solving skills for handling the difficulties in carrying out the action plan, providing support to develop self-efficacy, and expressing empathy for facing difficulties during the changing process. In the maintenance stage, identifying and handling factors associated with the risk of relapse and strengthening social support network are relevant counseling tasks. Finally, in the relapse stage, it is essential to provide supportive environment for learning from relapse and motivate the individual to recycle through the stages of change.

Instead of simply blaming adolescents for addictive behavior, it is noteworthy that Internet addiction may be a result of different ecological factors, particularly family factors. According to the family perspective, an adolescent with Internet addictive behavior represents a symptom of a dysfunction within a family rather than the individual's own maladjustment. For example, the child's Internet addictive behavior might be a symptom of the marital and parenting conflicts among the parents. Furthermore, it is proposed that change in an individual member of the family system would cause change in other family members as well as the whole family system. For example, a father changing his way in dealing with the son's Internet addictive behavior can improve his relation and communication with the son, and the son might react by becoming more willing to cooperate when the father disciplines his Internet use behavior. Actually, Internet addiction often occurs in the family context, which results in serious conflicts between the adolescents and their parents.

Against the above background, family counseling is considered important in treating Internet addicts. Several family-based counseling techniques are often adopted by Internet addiction treatment programs. The first one is reframing the symptoms of Internet addiction. The mutual influences of family members' interactions are emphasized in the counseling process. The interaction patterns regarding the adolescent clients' Internet addictive behavior (such as inconsistent parenting) are also examined to help the parents identify their influences. To broaden parents' understanding of their children's online behaviors, Internet addictive behavior can also be reframed as their children trying to fulfill their interpersonal needs through online activities. The second technique is dealing with unbalanced power. In some cases, the family power structure is upside down as children's superior computer knowledge might cause their parents feel powerless in disciplining their children's Internet use behavior. Support should then be given to the parents for performing appropriate parenting roles. External stoppers such as parent-child service plan provided by some Internet service providers, which enables the parents to control their children's online time, can be introduced as a way to empower the parents. The third technique commonly used in family counseling is resolution of conflicts. As there are continuous daily conflicts related to the Internet use behavior of the adolescent clients, such as when to stay off-line and the adolescent clients staying online during meal time, helping the parents and the adolescent clients to resolve the conflicts is a very important task. Skills for handling the emotions aroused by the conflicts are introduced and discussed with the parents and the adolescent clients. Facilitation of congruent communication which considers the self, other, and context in parent-child interaction is also important. This process attempts to find a solution which is acceptable by both the parents and the adolescent clients. The final one is discussion of the stages of change where the stages of change are explained and the parents are asked to identify which stage of change best described their children's current situation. The model helps to reframe the idea of "my child did not want to change" into "my child is in the pre-contemplation stage, which is the first step of change." It helps the parents to understand that change is a progressive process instead of simplifying as dichotomy of "change" and "not change." Parents are helped to identify appropriate actions to motivate their children in different stages of change.

In light of the different stages of change proposed in the change model, different therapeutic tasks are recommended in family counseling. In the pre-contemplation and contemplation stages, counselors help parents to handle emotions aroused by their children's Internet addictive behavior and to understand their children's needs and other problems behind the Internet addictive behavior and to identify the interaction patterns which maintain the Internet addictive behavior. In the determination and action stages, the counseling tasks include facilitation of direct and congruent parent-child communication (thus improving their mutual understanding and relationships), breaking the circular interaction patterns which maintain the Internet addictive behavior, and developing and strengthening interaction patterns of dealing with the conflict about Internet use, which in turn promote healthy Internet use habits. In the maintenance stage, the counselor maintains support and encouragement for developing healthy Internet use habits. In the relapse stage, the family counselor helps parents to handle emotion caused by relapse as well as to identify the improved interaction patterns and those still needed to improve. They also help the parents to maintain supportive family environment and motivating them for not giving up.

In addition to the treatment strategies at the individual and family levels, peer relation is another intervention target for adolescent problems. In the context of addiction, negative peer influence is an important risk factor for the development of both substance abuse and behavioral addiction. At the same time, peer support serves as a protective factor for adolescents to maintain healthy Internet use habit. As such, different supportive activities including volunteer groups and interest classes can be designed. The objectives of these activities may include improvement of social skills, establishment of supportive social network, realization of one's strengths and potentials, and promotion of healthy social engagement among the program participants. Typically, a peer support group for clients with Internet addiction is designed to help group members to recognize their own strengths and establish positive self-images, to experience how to honestly face themselves and other people so as to establish friendship with others, and to establish mutual respect, support, and caring relationships.

Similar to other self-help groups on addiction such as Narcotics Anonymous, Alcoholics Anonymous, and Gamblers Anonymous, there are self-help groups for people with Internet addiction. For example, the 12-step model adapted from Alcoholics Anonymous has been designed for members of Internet and Technology Addiction Anonymous (ITAA). These principles include:
  1. Honesty: Admit that one is powerless to overcome addictions and one's life is unmanageable.
  2. Hope: Believe that the power greater than oneself can help.
  3. Trust: Determine to give one's life to higher power as one understands it.
  4. Truth: Make a written moral inventory of oneself.
  5. Integrity: Admit to others that one is wrong.
  6. Change of heart: Become entirely ready that higher power removes all your character defects.
  7. Humility: Humbly ask a higher power to remove one's defects.
  8. Brotherly love: Confess to those one has harmed.
  9. Restitution and reconciliation: Make direct restitution to all persons one has harmed.
  10. Accountability: Admit one's mistakes promptly.
  11. Perseverance: Try hard to change.
  12. Service and spirituality: Spiritual awakening.
Interestingly, there is also a layman version of the 12-step model. The 12 steps include:
  1. Take a cup of tea or coffee in the morning and read your favorite newspaper before connecting to the Internet.
  2. Use both hands (i.e., use a knife and a fork) for breakfast. Do not use one hand for eating while using another hand to type the keyboard.
  3. Get dressed before noon (i.e., do not stay connecting to the Internet for the whole morning).
  4. Do other things such as cleaning the house, washing clothes, and planning dinner before thinking about the Internet.
  5. Write letters to those unfortunate friends and family who are not connected to the Internet.
  6. Call someone on the phone who is not connected to the Internet.
  7. Read a book before connecting to the Internet.
  8. Listen to those around you.
  9. Do not check e-mails during TV commercial breaks.
  10. Get out of the house at least once a week.
  11. Balance your checkbook and pay your bills before surfing on the Internet.
  12. You must go to bed because the Internet is always there.

Based on a thorough review of the literature on the intervention strategies and techniques used in the fields of substance abuse, a multilevel intervention model of Internet addiction was developed by Shek et al. (2009), which had the following characteristics. First, the program aimed at adolescents' controlled and healthy use of the Internet rather than the complete abstinence of Internet use. It was argued that Internet use is intrinsically neutral and a desirable treatment outcome should be healthy Internet use. Second, the program emphasized a progressive change in adolescents with Internet addiction behavior. The model of change stages by Prochaska and DiClemente was used to understand the needs of adolescent Internet addicts and their family members. Counseling tasks were also devised in relation to the different stages of change (i.e., pre-contemplation, contemplation, determination, action, maintenance, and relapse). The third feature of the intervention model was its utilization of motivational interviewing model based on the assumption that the responsibility and capability for change are within the client. Motivational interviewing techniques were used to elicit behavior change by helping clients to explore and resolve ambivalence. Fourth, systemic family view was adopted in the program, which considered Internet addiction a result of serious conflicts in the whole family system. As such, family-based counseling techniques are widely used in the treatment. Fifth, this program took a multilevel counseling model in which individual counseling component, family counseling component, and peer support component were developed. Finally, utilization of case work and group work was another feature of the project. Because of the importance of peer relations in adolescent development, peer support group approach was used as a supplement to the case work approach. Using group dynamics, mutual support, and modeling opportunities, group members can learn from each other. The detailed description of the features of the intervention model and the intervention process can be seen in Shek et al. (2009).

In short, several points are worth noting as far as existing intervention strategies of Internet addiction are concerned. First, a combination of different methods, such as individual counseling, family counseling, and group work, may be a better approach than solely relying on one specific intervention strategy to treat Internet addiction. Second, multidisciplinary collaboration involving different professionals such as medical doctor, clinical nurse specialist, family therapist, social workers, and clinical psychologist is important. Finally, the fact that there are few validated intervention programs in the area of Internet addiction deserves attention. In view of these, a multimodal intervention approach, such as the program developed by Shek et al. (2009), with factors at different levels (individual, social, and environmental) being fully considered, may well represent a promising direction for the intervention/prevention of Internet addiction in the future.


A review of the literature shows that there are conceptual limitations in the field of Internet addiction. The foremost limitation is that Internet addiction or problematic Internet use is defined in different ways. While some researchers use substance abuse symptoms to define Internet addiction, others conceive Internet addiction in terms of features of pathological gambling. Still others regard problematic Internet use as a normal developmental phenomenon which may eventually disappear when adolescents grow up. Obviously, how Internet addiction is defined determines the direction of research for the field. In the extreme case, if Internet addiction is regarded as a normal and transitional developmental phenomenon, prevention and treatment initiatives might not be even necessary. Besides, this question becomes more complicated when the issue of comorbidity is taken into account, that is, whether Internet addiction is part of other mental disorders or it should be listed as a separate form of mental disorder. Unfortunately, despite much effort, there is still no consensus on the definition of Internet addiction in the field.

The second limitation is that there is a paucity of theoretical models directly addressing the issue of Internet addiction. This review shows that scientific models on the antecedents, concomitants, and consequences of Internet addiction are scarce. Such models are indispensable in guiding empirical research on Internet addiction. Although some "general" psychological or sociological theories can be used to understand Internet addiction, empirical support for such models is neither consistent nor strong. In addition, theoretical accounts of the bidirectional influences between Internet addiction and developmental outcomes are almost lacking in the literature. Logically speaking, it is possible that there are mutual influences in Internet addiction and other psychological domains. As such, further studies should be conducted adopting an ecological approach to examine how individual factors (e.g., economic disadvantage), family factors (e.g., family beliefs, family functioning), and social factors (e.g., poverty and social exclusion) are related to Internet addiction.

Besides conceptual issues in the field, there are several methodological problems in the literature of Internet addiction that deserve researchers' attention. The first limitation is that most of the measures of Internet addiction are quantitative in nature, usually relying on questionnaires developed in the West. While a positivistic approach represents the dominant research paradigm in social science research and behavioral medicine, there are views pointing out its weaknesses and arguing for the greater use of qualitative methods. In fact, qualitative studies employing techniques such as drawing, open-ended questions, and in-depth interviews to understand Internet addiction and related behavior should be considered.

In non-Western contexts, with the exception of a few attempts, instruments assessing Internet addiction are mostly translated Western measures. In a non-Western context, the issue that should be addressed is whether an "emic" (insider) or "etic" (outsider) approach should be used to examine Internet addiction in different cultural contexts. Another difficulty with the existing measures of Internet addiction is on the issue of validation. Irrespective of whether the measure of Internet addiction is imported or indigenously developed, one important requirement is that the measures should be validated. Unfortunately, not all researchers are conscious of this requirement. There are several observations that should be borne in mind. In the first place, test-retest reliability in quantitative measures and intra- and inter-rater reliability in qualitative assessment of Internet addiction are not commonly carried out. Secondly, convergent and discriminant validities are seldom established in a single validation study. Furthermore, few studies have conducted confirmatory factor analysis to uncover the underlying structure of the scales.

In addition, the present review shows that most of the existing studies on Internet addiction are cross-sectional in nature. Although cross-sectional studies, such as surveys of psychosocial correlates of Internet addiction, are useful to understand Internet addiction at a single time point, such designs are inadequate if the researchers wish to investigate the antecedents and consequences of Internet addiction. Obviously, although cross-sectional studies can help to identify the correlates of Internet addiction, causal relationships involved cannot be clearly established. As such, longitudinal research designs represent a more sensitive approach in examining the causal relationships between Internet addiction and other factors.

Generalizability is another methodological concern that researchers have to consider. If a research study is to claim universal validity, it must be generalizable to different participants at different time points and in different places. Generally speaking, there are two levels at which comparative studies on Internet addiction in a non-Western context (e.g., African context) should be carried out. At the first level, findings based on African people may be compared to findings obtained from non-African people. Such cross-cultural studies are important because they can give some ideas about the degree of universalism versus cultural relativism of relationships involving Internet addiction in African people. At the second level, because Africa is a big continent and there are regional differences involving different ethnic groups, studies involving African people from different parts of Africa are also important, i.e., comparative studies within the diverse African cultural contexts. Such research is at present nonexistent.

It is noteworthy that there are other common methodological limitations in the existing studies on Internet addiction. First, consistent with other areas of quantitative psychology, it is rare for researchers to collect data on Internet addiction based on random samples. This practice obviously undermines the generalizability of the related findings. Second, in those studies utilizing statistical tests of significance, it is not a common practice for researchers to report the related effect size of the significant findings, a practice increasingly required in major journals. Third, for studies where multiple tests of correlation or differences are reported, the issue of inflated Type I error is not commonly addressed. Finally, in studies where multivariate analyses are performed, it is uncommon for researchers to examine the stability of the multivariate statistical analyses.

As far as the practical limitations of the literature on Internet addiction are concerned, three observations deserve attention. First, there are very few effective prevention programs for Internet addiction. Most of the existing programs use the prevention strategies and techniques for substance abuse and pathological gambling to guide the design of the related prevention programs. Second, although there are many treatment programs throughout the world claiming that they can be used to treat Internet addiction, evaluation findings for the existing programs are sparse. In fact, there are no programs that have been consistently shown to be effective via the use of multiple clinical trials. Finally, instead of seeing Internet addiction as a separate adolescent problem that should be prevented, one must ask whether adolescent developmental issues have common roots and whether promotion of psychosocial competencies in adolescents can help to "prevent" different types of adolescent developmental issues.

Conclusions and Future Directions

Several conclusions can be highlighted from the present review. First, despite the fact that Internet addiction is a growing global problem, there are different conceptions of Internet addiction. Second, different measures on Internet addiction are available, but most are developed in the West and indigenously developed measures in non-Western contexts are few. Third, although some studies have generated profiles on Internet addiction in different places, the related findings are not consistent across studies. Fourth, the development of theories of Internet addiction and research studies in this area has progressed slowly. Fifth, although general micro and macro theories can be used to understand Internet addiction, specific theories on Internet addiction are lacking. Sixth, while a few sociodemographic, psychological, and family correlates of Internet addiction have been identified, the findings are inconclusive. Finally, conceptual, methodological, and practical limitations and issues in the existing studies discussed above are worth noting and must be considered by researchers in the field.

With reference to these limitations, several future research directions are proposed. First, research should be carried out to examine the conceptions and measurement of Internet addiction in both Western and non-Western contexts. Second, integrated theoretical models on Internet addiction should be constructed. Third, qualitative studies and mixed-method research should be carried out. Fourth, the quest for longitudinal studies of Internet addiction is in order. Finally, conducting translational research on Internet addiction should be attempted.

Further Reading

  • American Psychiatric Association (1994) Diagnostic and statistical manual of mental disorders: DSM-IV. 4th ed. Washington, DC: American Psychiatric Association
  • Beard KW (2005) Internet addiction: a review of current assessment techniques and potential assessment questions. CyberPsychol 8:7-14
  • Davis RA (2001) A cognitive-behavioral model of pathological internet use. Comput Hum Behav 17:187-195
  • Griffiths M (1998) Internet addiction: does it really exist? In: Gackenbach J (ed) Psychology and the internet. Academic, San Diego
  • Holden C (2001) Behavioral addictions: do they exist? Science 294:980-982
  • Kubey RW, Lavin MJ, Barrows JR (2001) Internet use and collegiate academic performance decrements: early findings. J Commun 51:366-382
  • Morahan-Martin J, Schumacher P (2000) Incidence and correlates of pathological Internet use among college students. Comput Hum Behav 16:13-29
  • Murray B (1996) Computer addictions entangle students. APA Monitor 27:38-39
  • Prochaska J, DiClemente C (1992) Stages of change in the modification of problem behaviours. In: Hersen M, Eisler R, Miller P (eds) Progress in behaviour modification, vol 28. Sycamore, New York
  • Shaffer HJ, Hall MN, Vander Bilt J (2000) Computer addiction: a critical consideration. Am J Orthopsychiat 70:162-168
  • Shaffer HJ, LaPlante DA, LaBrie RA et al (2004) Toward a syndrome model of addiction: multiple manifestations, common etiology. Harvard Rev Psychiat 12:367-374
  • Shapira NA, Goldsmith TD, Keck PE, Khosla UM, McElroy SL (2000) Psychiatric features of individuals with problematic internet use. J Affect Disorders 57:267-272
  • Shek DTL, Tang VMY, Lo CY (2008) Internet addiction in Chinese adolescents in Hong Kong: assessment, profiles, and psychosocial correlates. Sci World J TSW Child Health Hum Dev 8:776-787
  • Shek DTL, Tang VMY, Lo CY (2009) Evaluation of an internet addiction treatment program for Chinese adolescents in Hong Kong. Adolescence 44:359-373
  • Wallace P (1999) The psychology of the internet. Cambridge University Press, New York
  • Young KS (1999) Internet addiction: symptoms, evaluation, and treatment. In: VandeCreek L, Jackson T (eds) Innovations in clinical practice: a source book, vol 17. Professional Resource Press, Sarasota
  • Young KS, de Abreu CN (eds) (2010) Internet addiction: a handbook and guide to evaluation and treatment. Wiley, Hoboken