|Year : 2016 | Volume
| Issue : 2 | Page : 145-154
“One level more:” A narrative review on internet gaming disorder
Subrata Naskar1, Robin Victor2, Kamal Nath2, Chiradeep Sengupta3
1 Department of Neuropsychiatry, Institute of Neurosciences, Kolkata, West Bengal, India
2 Department of Psychiatry, Silchar Medical College and Hospital, Silchar, Assam, India
3 Department of Psychiatry, Fakhruddin Ali Ahmed Medical College, Joti Gaon, Assam, India
|Date of Web Publication||13-Jun-2017|
9G, Avenue 1st Road, Kolkata - 700 075, West Bengal
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Due to explosive growth in technology and internet usage in the last few years, internet gaming disorder (IGD) has manifested as rapidly growing public health problem mainly affecting the teen and preteen population worldwide. It has a negative impact upon physical, psychological, social, and occupational functioning of the affected individual, often leading to severe consequences. It was only recently that it has been recognized as a separate diagnosable disorder in the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition. Not much data is available regarding the exact prevalence and the various sociodemographic, clinical, and other risk factors to identify the individuals vulnerable to develop this disorder, especially in the developing countries such as India. According to a recent report, India ranks 22nd in the list of highest revenue-generating countries from gaming-related businesses, thus highlighting the magnitude of risk faced by Indian population. The aim of this review is to provide an insight about the disorder to identify the risk factors and clinical features, to understand the effect of IGD upon the psychological and physical health with a special focus on neural changes, and to provide information on the various upcoming preventive and treatment strategies.
Keywords: Gaming addiction, internet gaming disorder, pathological gaming, prevalence, treatment
|How to cite this article:|
Naskar S, Victor R, Nath K, Sengupta C. “One level more:” A narrative review on internet gaming disorder. Ind Psychiatry J 2016;25:145-54
The world has changed rapidly in the past two decades. Kids and adults alike now search for the latest gaming platforms with the highest processing power chipsets and an internet plan with the fastest surfing speed. The arrival of computer and internet has changed the fundamental childhood needs very rapidly. Computer and smartphone-based games have revolutionized the world and the concept of virtual reality. The attraction of losing oneself in the realms of virtual reality that has been provided by those platforms is beyond anything. But, what happens in reality when people get busy losing themselves in the “virtual reality?” The following two case vignettes (quoted as presented by their authors) will give us an idea about that.
“Messrs. A and B were two unmarried brothers, belonging to a nuclear family of upper socioeconomic class of urban background of New Delhi, India. Mr. A is 19 years old, studying in 12th standard while Mr. B is 22 years old, studying in 2nd year of engineering in Haryana, India. The problem began when both brothers used to stay together at home and started playing online game with their virtual Internet friends from different countries. The duration of online gaming progressed from 2 to 4 hours per day to 14 to 18 hours per day over the initial few months. The behavior and self-care of these brothers became so compromised and disorganized that, while playing the games, they urinated and defecated in their clothes, did not change clothes for days, did not bathe, skipped their meals, did not pick up phones, or open doors even to their parents. Their home was robbed twice of cash and costly articles in their presence, during the last 2 months while they were preoccupied in playing online games.”
“An 18-year-old boy had excessive use of video game for the last 2 years. Playing led to losing interest in studies as well as getting low academic grades. The other dysfunctions were seen in the form of decreased self-care, disturbance in biological functions, avoiding contact with others, and behavioral changes in the form of irritability whenever advised to stop accessing video game. The parents had psychiatric distress on 12-item General Health questionnaire, and family burden interview schedule indicates disturbance in leisure activities, family routine, family interaction, physical and mental health. They attributed it to helplessness to manage the user's psychosocial dysfunctions. It also starts affecting their lifestyle in terms of decreased engagement in pleasurable activities, disturbance in sleep attributable to frequent checking of user's activities at night, and interpersonal problems.”
| Why Play Games? the Principal Motives|| |
It was Bartle  who first formulated a hypothesis based on motivational approach, he classified the motives according to the playing styles and classified the gamers in four categories. The “achievers,” “explorers,” “socializers,” and “killers.” The achievers were those who game to attain respect of the virtual society and to gain some reward which may be a “level up” or a “new power.” Their actions are goal directed, i.e., to complete the missions of the game. The “explorers” game in search of sudden pleasures to discover new in-game structures and story. The “socializers” game to socialize, chat, and be a part of something like a team or community. Finally, comes the “killers,” also known by the slang “trolls” who use the gaming platform to bully on fellow gamers or annoy them in anyway.
Yee  made a novel attempt to categorize the motivations behind internet gaming. After testing a 40-item questionnaire, he reported three major motivational components; the first component is again subdivided into three subcomponents, which include being “in-game rank reputation” or “advancement” in the game. This includes leveling up, acquiring a new status or skill of the game character. “Mechanics” includes optimizing the game to face harder challenges. “Challenge” where the player dominates other players and earn respect of the gaming community. The second component is “social factor.” It includes chatting with fellow gamers, socializing, being part of communities, making friends, and forming teams to take on rival teams. The third component again has three subcomponents, namely, “discovery” where the players discover new items, weapons, or a new in-game world to explore, “escapism” where the gamer can escape into the virtual world forgetting about all the problems and hindrances of the real world, which leads to a subjective mood elevation, and “a coping strategy to deal with everyday problems” and finally, “role playing” where the gamer acquires a new persona according to his/her fantasy.
Recent studies which investigated the psychological predictors of problems in gambling postulated two important predictors. According to Billieux et al., it is the “positive urgency” and “immersion” that dominate and control the behavior of a gamer. Positive urgency, which is defined as “the tendency to act rashly while in a positive mood” makes it difficult for the gamer to avoid online gaming and let go of the euphoria. Secondly, according to them, immersion in the realms of virtual reality when faced with negative affect to avoid real-life problems is again one of the principal motivations for gamers.
| The Genres|| |
Apperley in his article titled, “Genre and game studies: Toward a critical approach to video game genres” classified the video games in various genres. Based on the type of interaction of the player, those genres are platform, mode, and milieu. Whereas according to the type of gameplay, the video games are further classified into four major genres, those being simulation, strategy, action, and role playing. Details of these genres are shown in [Table 1]. However, among all these genres, it is the massively multiplayer online role-playing games (MMORPGs) that have currently gained popularity beyond anything.
| Massively Multiplayer Online Role-playing Game Explained|| |
Unlike others, MMORPGs have some particular characteristics. Those are: (a) Presence of a “persistent virtual world” with a huge user base. A “persistent virtual world” is a virtual world that is independent of a user's login status; the world will exist and will be modified in the absence of a particular user by the actions of other users who are online. (b) Player has the ability to create an avatar, which he/she will be able to modify according to the needs. This includes creation of a body structure, face, attire, weapons, powers, race, clan, gender, profession, morality, and many others. (c) Advancement will be rewarded by “level up” which may be an addition of skills, powers, or unlocking of other missions. (d) Players are able to socially interact with fellow gamers through the in-game characters and can form alliances to defeat their opponents.
According to data cited from mmos.com, some of the most popular MMORPGs currently are Dungeon Fighter Online, Fantasy Westward Journey, World of Warcraft, and RuneScape.
| Internet Addiction and Internet Gaming Disorder – same Entity or Different?|| |
Internet addiction (IA) and internet gaming disorder (IGD) are not the same entity according to Griffith and Pontes. They pointed out that many researchers have used “the internet addiction questionnaire” or “other nonvalidated versions of the tests to diagnose and assess the severity of online gaming addiction.” According to the same report, this is possibly the reason why the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) regarded IGD and IA disorder (IAD) as the same disorder. Király et al. investigated the demographic variables and behavioral pattern among the IGD and IAD groups taking a total sample size of over 2000 adolescents. According to them, the differences between the groups are quite significant. They reported that individuals with IAD are usually males, invest a significant amount of time online doing any kind of online activities such as social networking, chatting, watching social media including gaming, whereas gaming disorder is specifically associated with gaming online. They suggested that these two entities are entirely “conceptually different behaviors.” A cross-cultural study  that was conducted across two different continents taking participants from Sweden, Germany, Taiwan, and China also supported the view of Griffith and Pontes.
| Internet Gaming Disorder in the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition|| |
Over the years, there had been debates whether to classify IGD as a separate entity, finally the recognition came in 2013 with the arrival of the DSM-5. It states that “Persistent and recurrent use of the internet to engage in games, often with other players, leading to clinically significant impairment or distress as indicated by five (or more) of the following in a 12-month period” is considered IGD. Those criteria being preoccupation, withdrawal, tolerance, unsuccessful attempts to control, loss of interests, continued excessive use despite psychosocial problems, deceiving, escape, and functional impairment.
| Prevalence of Internet Gaming Disorder|| |
The prevalence of IGD varies worldwide and is estimated to be between 0.2% and 8.5%., The severity and prevalence of IGD are found to be higher in the Asian countries than that of the West. This variable prevalence rate may be due to the use of different types of measurement instruments, different cutoffs, use of self-reporting questionnaires  in most studies, and due to diversity in conceptualization. Some reviews claim that Korea reported to have the highest known prevalence, where up to 50% of the adolescents are presumed to be addicted to gaming, and IGD is reported to be a significant public health problem there and up to 24% of those diagnosed as having IA need hospitalization. However, these reviews and studies have considered IGD and IAD as the same disorder. As we have discussed before that IAD and IGD are distinct entities with some overlapping characteristics, it will not be wise to consider the prevalence of one as that of others. [Table 2] summarizes the findings of some studies conducted across the world.
|Table 2: Prevalence rates of internet gaming disorder as reported by various studies|
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| The Risk Factors|| |
Most of the available literature have suggested that IGD is more prevalent among males than females., Ko et al. commented that they found significant gender differences in the motives for online gaming. According to them, increasing age, poor self-esteem, and daily life satisfaction were associated with more severe online gaming addiction among males only. Muller et al. studied a sample of 12,938 children and adolescents from seven countries across Europe; they reported that “adolescents with IGD reported, being from broken home, divorced parents.” Wang et al. reported that gaming addiction has a positive association with academic performance, gender, perceived family harmony, relationship with classmates, and the number of close friends; whereas they found no association with age, grade in which subject is studying, number of family members/siblings, parental marital status, education status of parents, socioeconomic status, and ownership of gaming devices.
There are some studies that tried to evaluate if the genre of the game has anything to do with intensity of gaming addiction. Donati et al. in their study conducted in 2015, among 701 male adolescents, found that the most popular genre is action (88%) followed closely by casual (86%) and sports (84%) games. Real-time strategy (RTS) (32%) games, retro games (30%), and massively-multiplayer online (27%) were the less practiced. They also found that there is a statistically significant and positive correlation between time spent on gaming and gaming versatility (the gaming versatility score was calculated by summing the number of video game genres played). Eichenbaum et al. conducted a study in the United States of America in 2015, among 4744 university students, and reported that IGD scores elevated rapidly with time playing RTS and real person fiction games than for action games. Two years earlier to those two studies, in 2013, Lemmens et al. conducted a study to find the correlations between game genres and IGD among 2442 individuals in the Netherlands. They found a stronger correlation between online gaming and IGD than offline ones. Among the genres, they found that time spent by playing role-playing games (offline and online) and shooters correlated positively with IGD; the correlation was stronger for online play. Wang et al. reported a significant association between gaming addiction and various factors such as longer average time of gaming per week, higher frequency as well as longer period of spending money on gaming.
| Personality Traits|| |
Braun et al. in their study conducted in 2015 on 2891 individuals (2421 males, 470 females) between 13 and 65 years of age applied the Big Five Inventory-SOEP and measured each of the five personality dimensions, namely, neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness among regular gamers, nongamers, and gaming addicts. They reported “a positive association between neuroticism and IGD and a negative association between extraversion, conscientiousness, and IGD” but could not find any association between openness, agreeableness, and IGD. Seven years earlier in 2008, Kim et al's. study  on 1471 individuals concluded that narcissistic personality traits, aggression, and self-control of an individual may predict the severity of gaming addiction in him/her.
| A Gene for Gaming!|| |
Excessive internet gaming individuals show a higher than normal reward dependency. An increased prevalence of the DRD2 Taq1A1 and COMT alleles has been reported in these individuals. In adolescent gamers, the Taq1A1 allele was found to be associated with reward dependence than other groups.
| Neurochemistry – dopamine Again!|| |
The role of dopamine as a reward mediator has been long established. A study published in “Nature” in 1998 using 11 C-labeled raclopride and positron emission tomography scans has shown that dopamine is released in human striatum while video gaming, like any goal-directed motor task. The release was highest in ventral part of striatum and positively correlated with performance level in gaming.
A study in China using 99mTc single photon emission computed tomography reported that dopamine transporter in striatum in individuals with IGD is significantly decreased compared to healthy controls. Various studies conducted on substance-addicted individuals reported similar findings and are highly suggestive of brain dopaminergic functional impairment.
| Comorbidities Associated With Internet Gaming Addiction|| |
IGD is thought to be a gradually progressive behavior, with a chronic course deteriorating over time. The pathological gaming behavior may lead to significant physical and mental health problems as reported by numerous literary evidences. Lehenbauer-Baum et al. reported that addicted gamers have a higher association with psychopathologies than controls. They found that addicts scored higher in Beck's Depression Inventory and Social Phobia Inventory and are less agreeable, thorough, and emotionally less stable. They also reported that the intensity of anger, guilt, anxiety, and envy felt by the addicted players is more severe than controls. Achab et al. reported that addicts are severely sleep deprived and have a 3 times more odds of having diurnal sleepiness than normal gamers. Li et al. showed that pathological gaming behavior is more related to self-discrepancy, depression, and escapism. They inferred that there is a definite relationship between escapism and actual-ideal self-discrepancies which is mediated by depression. Similarly, pathological gaming and depression are interrelated which is mediated by escapism. Van Rooij et al. tried to evaluate the hypothesis that whether substance using adolescents are more prone to problematic gaming or not. Their results showed that “nicotine, alcohol, and cannabis using boys were almost twice more likely to be problematic gamers (PGs);” alcohol and cannabis using girls also showed higher propensity than controls. Yau et al. in their review reported that PGs are 2.77 times more likely to get diagnosed as having ADHD; they also reported an association of problematic gaming with mood disorder and substance use disorders (particularly those involving tobacco and “hard” drug use). In 2014, Jalink et al. published a review of 38 papers which reported injuries sustained by the use of handheld gaming devices (Nintendo, Game and Watch, Famicom, Game Boy, Virtual Boy, iQue, GameCube, and Wii). They reported cases such as epilepsy (Nintendo epilepsy), which is seizure due to rapid change of on-screen patterns, auditory hallucinations (Nintendo hallucination), tendinitis of wrist, thumb, and hand due to long hours of play (nintendinitis or nintendonitis), palmer ulcerations, enuresis, encopresis, and “motion-sensitive Wii remote-related musculoskeletal problems and various traumas.”
| Associated Behavioral Issues With Internet Gaming Disorder|| |
Addicted gamers experience significantly more irritability, agitation (less calmness), sadness, and often report of confusing real life with the virtual world. Van Rooij et al. found a strong association between problematic gaming and decreased psychosocial well-being and low school performance. They commented that, irrespective of gender, depressive mood, social anxiety, negative self-esteem, and loneliness prevailed in PGs. A study published in 2011 on 540 adolescents in the Netherlands tried to evaluate the relationship between aggression and pathological gaming and yielded some interesting results. They reported that pathological gaming is progressive in nature and if not controlled may displace important day-to-day activities. Another important finding was that, regardless of involvement of violence in gameplay, pathological gamers self-reported increased aggressive feelings after 6 months; however, this finding was found only in males. They also commented that increase in aggressive behavior is mainly related to the time spent in playing violent games specifically, not just time spent in playing games. These data predict a possibility of physical aggression in pathological gamers in future life, which is also supported by numerous other studies. Addicted gamers show low social participation and there is a significant negative relationship between social skills of addicted gamers and selection of home as the place of gaming. Kim et al. conducted a study on 3041 adults in Korea, which found that gamers at risk of addiction are impulsive, exhibit more aggression than healthy controls, and there is a 5 times more risk of attempted suicide in them.
| Does Excessive Gaming Change One's Brain? What Does Neuroimaging Studies Say?|| |
Recent studies have implicated numerous brain regions for the possible causation of compulsive gaming leading the conceptualization of internet gaming addiction similar to that of impulse control disorder and behavioral addiction. Abnormal activity is seen especially in the orbitofrontal cortex, striatum, nucleus accumbens, cingulate cortex, and sensory regions. These areas are implicated for “somatic representation of previous processes,” impulse control, and reward processing. [Table 3] summarizes the findings as conducted by the recent studies ,,,,,,,,, conducted to identify those regions.
|Table 3: Inputs from neuroimaging studies performed on individuals with internet gaming disorder|
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| Scales for Identification and Assessment of Internet Gaming Disorder|| |
Researchers have come forward with various scales to identify and assess the severity after internet gaming addiction surfaced as a viable public health problem. Lemmens et al. in 2015 tested a long (27-item) and short (9-item) polytomous scale and a long (27-item) and a short (9-item) dichotomous scale for finding validity among 2444 Dutch adolescents and adults, aged 13–40 years. All the four scales were reported to provide satisfactory results. Vadlin et al. developed a screening tool for gaming addiction in adolescents – the Gaming Addiction Identification Test in 2012 which is a 15-item tool measured on 5-point Likert scale and reported good content validity in assessing gaming addiction. Later, they developed a parent version of the scale with the same number of items.
| Prevention and Treatment|| |
Although currently many studies have suggested various preventive strategies and treatment outcomes on individuals with IA, there is a huge scarcity of literature mainly of longitudinal controlled studies on the same about internet gaming addiction. Griffiths and Meredith in their article in 2009 laid down some guidelines to be followed for prevention and treatment purpose [Table 4].
|Table 4: Griffiths et al.'s recommendation for prevention of internet gaming addiction|
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Online support forums
A number of online support forums such as Computer Gaming Addicts Anonymous (http://cgaa.info/discussion-forum/) and On-Line Gamers Anonymous (http://www.olganon.org/home) have sprung up in recent years which provide both information and internet-based treatment approach. The approach is mainly based heavily on the 12-step program of recovery (honesty and acceptance, hope, faith or trust, action and courage, integrity, willingness, humility, love, justice, perseverance, spirituality or beauty, and service) used by such groups as Alcoholics Anonymous and Gamblers Anonymous.
Cognitive behavior therapy
It is believed that cognitive behavior therapy (CBT) has got a role in the treatment of IGD. Identification of faulty cognition, distorted emotions, and application of proper coping skills are the ground rules for CBT. In a very recent study, King and Delfabbro (2016) tried to evaluate the cognitive psychology of internet game addicts. They found four cognitive factors that drive the behavior: “(a) beliefs about game reward value and tangibility, (b) maladaptive and inflexible rules about gaming behavior, (c) over-reliance on gaming to meet self-esteem needs, and (d) gaming as a method of gaining social acceptance.” They recommended further longitudinal studies using CBT to address these areas in the future.
A cognitive client-centered motivational approach has been suggested by some authors, the idea is to provide motivation to a person with gaming addiction, most of whom are coerced in various treatment programs. The Develop discrepancy, Avoid argumentation or confrontation over the behaviour, Roll with resistance, Express empathy, Support self-efficacy strategy is mainly applied on the area of ambivalence and resistance.
Treatment with the self-discovery camp
A paper published by Sakuma et al. in 2016 suggested an innovative way of dealing with internet gaming addiction. They suggested deaddiction by intensive treatment in a therapeutic residential camp, which they called “Self-Discovery Camp.” The camp did not allow clients to bring any digital equipment.
Components of therapy regimen
- 14 sessions of CBT by psychologists
- Three medical lectures by doctors
- Eight sessions of personal counseling
- One workshop
- Outdoor activities such as cooking, walk rally, trekking, and woodworking.
Objective of self-discovery camp
- To foster awareness of health, wellness, and a well-regulated life
- To experience communication without the Internet or digital devices
- To collaborate with others and solve problems.
College student volunteers were recruited as mentors. Participation was voluntary for everyone including the clients with IGD and the motivators who were college students majoring in education. The program reported a significant reduction of gaming behavior after only 3 months of therapy.
Virtual reality treatment program
Another innovative paper from Korea by Park et al. reported improvement of gaming behavior similar to that achieved by CBT, which they called virtual reality treatment program. This program consists of eight sessions, each sessions consisting of three steps preceded by a preinterview.
Preinterview: In this phase, the demographic information and photograph of participants were taken, their voices were recorded, and each participant had to answer two questions: “(a) What are the most precious things in your life? (b) What is the most difficult problem caused by your excessive game play?”
- Relaxation (5 min) - This phase was done to relax the persons by exposing to relaxing sounds and video
- Simulation of a high-risk situation (10 min) –-This phase was to induce craving in the client and was done by exposure to gaming cues from the game that he/she plays
- Sound-assisted cognitive reconstruction (10 min) - An aversive noise causing anxiety and annoyance to the participant was played in the most exciting high-risk situations which was paired with stimuli illustrating the aversive consequences of long-term pathological gaming (this was done by integrating participant's photographs in aversive situations depicting long-term consequences of pathological gaming). The session ended by playing the initial recording of the participant's answer to the question, “What are the most precious things in your life?”
The treatment protocol reported similar efficacy to that of CBT but within a short period of time.
Han et al. studied the role of bupropion-sustained release formulation in IGD. After a 6-week trial, they concluded that there is a significant reduction in craving for internet video game play, total game play time, and cue-induced brain activity in dorsolateral prefrontal cortex. However, King and Delfabbro  reviewed three studies which suggested bupropion or methylphenidate for IGD and compared their efficacy to psychological treatments. They found no significant differences in terms of their efficacies.
| Indian Perspective|| |
According to a web report, the current consumer revenue generated by various gaming companies from India only is 469,702,000 USD which also claims that India is the 22nd highest revenue generator. This figure highly suggests that Indian population probably is in a position quite vulnerable to IGD, especially the youth population. However, a search for relevant literatures on IGD from India yielded a meager few, most of which are isolated case reports. Prevalence studies on IA are currently getting published from various corners of the country, but none such has been found for IGD (to the best of our knowledge). Considering that IGD and IA have a similar approach for treatment, treatment options are available only at a few centers of our country. The National Institute of Mental Health and Neurosciences, India, has started the Services for Healthy Use of Technology Clinic, which provides help and services to those with a habitual pattern of excessive use of technology to the extent of impairment in other areas of functioning. Services include screening, cognitive reshaping, teaching of coping skills, and replacement of problematic technology use by healthy activities.
| Conclusion|| |
Although being recognized by the DSM-5 as a separate entity, IGD has yet not received its recognition as a viable public health problem. There have been some prevalence studies worldwide, but the actual magnitude of the disorder is yet to be revealed, especially in the developing countries such as India. Second, there is still diagnostic dilemma regarding IA and IGD, which needs to be cleared. Finally, the most important of all, researches regarding treatment options and success on this matter are still in infancy and need to pick up. Not only is there an urgent need for an effective and definitive clinical guideline of treatment, but also there is an urgent need to spread awareness and establishment of specialized clinics countrywide to provide solutions to those who are in desperate need to get out of the virtual reality.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Sachdeva A, Verma R. Internet gaming addiction: A technological hazard. Int J High Risk Behav Addict 2015;4:e26359.
Antochi R, Stavrakaki C, Emery PC. Psychopharmacological treatments in persons with dual diagnosis of psychiatric disorders and developmental disabilities. Postgrad Med J 2003;79:139-46.
Bartle R. Designing Virtual Worlds. Vol. p. New Riders: New Riders Publishing In.; 2004. p. 741.
Yee N. Motivations for play in online games. Cyberpsychol Behav 2006;9:772-5.
Kuss DJ. Internet gaming addiction: Current perspectives. Psychol Res Behav Manag 2013;6:125-37.
Billieux J, Chanal J, Khazaal Y, Rochat L, Gay P, Zullino D, et al.
Psychological predictors of problematic involvement in massively multiplayer online role-playing games: Illustration in a sample of male cybercafé players. Psychopathology 2011;44:165-71.
Cyders MA, Smith GT. Emotion-based dispositions to rash action: Positive and negative urgency. Psychol Bull 2008;134:807-28.
Apperley TH. Genre and game studies: Toward a critical approach to video game genres. Simul Gaming 2006;37:6-23.
Király O, Griffiths MD, Urbán R, Farkas J, Kökönyei G, Elekes Z, et al.
Problematic internet use and problematic online gaming are not the same: Findings from a large nationally representative adolescent sample. Cyberpsychol Behav Soc Netw 2014;17:749-54.
Montag C, Bey K, Sha P, Li M, Chen YF, Liu WY, et al.
Is it meaningful to distinguish between generalized and specific Internet addiction? Evidence from a cross-cultural study from Germany, Sweden, Taiwan and China. Asia Pac Psychiatry 2015;7:20-6.
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders [Internet]. 2013.
Hur MH. Demographic, habitual, and socioeconomic determinants of Internet addiction disorder: An empirical study of Korean teenagers. Cyberpsychol Behav 2006;9:514-25.
Gentile D. Pathological video-game use among youth ages 8 to 18: A national study. Psychol Sci 2009;20:594-602.
Kuss DJ, Griffiths MD, Karila L, Billieux J. Internet addiction: a systematic review of epidemiological research for the last decade. Curr Pharm Des [Internet] 2014;20:4026-52. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24001297
. [Last cited on 2017 Feb 22].
Festl R, Scharkow M, Quandt T. Problematic computer game use among adolescents, younger and older adults. Addiction 2013;108:592-9.
Ahn JY. Korean Policy on Treatment and Rehabilitation for Adolescents' Internet Addiction. In: International Symposium on the Counseling and Treatment of Youth Internet Addiction, Seoul, Korea; 2007. p. 49.
Donati MA, Chiesi F, Ammannato G, Primi C. Versatility and addiction in gaming: The number of video-game genres played is associated with pathological gaming in male adolescents. Cyberpsychol Behav Soc Netw 2015;18:129-32.
Ko CH, Yen JY, Chen CC, Chen SH, Yen CF. Gender differences and related factors affecting online gaming addiction among Taiwanese adolescents. J Nerv Ment Dis 2005;193:273-7.
Eichenbaum A, Kattner F, Bradford D, Gentile DA, Green CS. Role-playing and real-time strategy games associated with greater probability of internet gaming disorder. Cyberpsychol Behav Soc Netw 2015;18:480-5.
Lemmens JS, Hendriks SJ. Addictive online games: Examining the relationship between game genres and internet gaming disorder. Cyberpsychol Behav Soc Netw 2016;19:270-6.
Rehbein F, Kleimann M, Mössle T. Prevalence and risk factors of video game dependency in adolescence: Results of a German nationwide survey. Cyberpsychol Behav Soc Netw 2010;13:269-77.
Wang CW, Chan CL, Mak KK, Ho SY, Wong PW, Ho RT. Prevalence and correlates of video and internet gaming addiction among Hong Kong adolescents: A pilot study. ScientificWorldJournal 2014;2014:874648.
Braun B, Stopfer JM, Müller KW, Beutel ME, Egloff B. Personality and video gaming: Comparing regular gamers, non-gamers, and gaming addicts and differentiating between game genres. Comput Human Behav 2016;55:406-12. Available from: http://www.linkinghub.elsevier.com/retrieve/pii/S0747563215301722
. [Last cited on 2016 Jul 10].
Kim EJ, Namkoong K, Ku T, Kim SJ. The relationship between online game addiction and aggression, self-control and narcissistic personality traits. Eur Psychiatry 2008;23:212-8.
Han DH, Lee YS, Yang KC, Kim EY, Lyoo IK, Renshaw PF. Dopamine genes and reward dependence in adolescents with excessive internet video game play. J Addict Med 2007;1:133-8.
Koepp MJ, Gunn RN, Lawrence AD, Cunningham VJ, Dagher A, Jones T, et al.
Evidence for striatal dopamine release during a video game. Nature 1998;393:266-8.
Hou H, Jia S, Hu S, Fan R, Sun W, Sun T, et al.
Reduced striatal dopamine transporters in people with internet addiction disorder. J Biomed Biotechnol 2012;2012:854524.
Lehenbauer-Baum M, Klaps A, Kovacovsky Z, Witzmann K, Zahlbruckner R, Stetina BU. Addiction and engagement: An explorative study toward classification criteria for Internet gaming disorder. Cyberpsychol Behav Soc Netw 2015;18:343-9.
Achab S, Nicolier M, Mauny F, Monnin J, Trojak B, Vandel P, et al.
Massively multiplayer online role-playing games: Comparing characteristics of addict vs non-addict online recruited gamers in a French adult population. BMC Psychiatry 2011;11:144.
Li D, Liau A, Khoo A. Examining the influence of actual-ideal self-discrepancies, depression, and escapism, on pathological gaming among massively multiplayer online adolescent gamers. Cyberpsychol Behav Soc Netw 2011;14:535-9.
Van Rooij AJ, Kuss DJ, Griffiths MD, Shorter GW, Schoenmakers MT, Van DE Mheen D. The (co-) occurrence of problematic video gaming, substance use, and psychosocial problems in adolescents. J Behav Addict 2014;3:157-65.
Yau YH, Crowley MJ, Mayes LC, Potenza MN. Are Internet use and video-game-playing addictive behaviors? Biological, clinical and public health implications for youths and adults. Minerva Psichiatr 2012;53:153-70.
Jalink MB, Heineman E, Pierie JP, ten Cate Hoedemaker HO. Nintendo related injuries and other problems: Review. BMJ 2014;349:g7267.
Lemmens JS, Valkenburg PM, Peter J. The effects of pathological gaming on aggressive behavior. J Youth Adolesc 2011;40:38-47.
Zamani E, Chashmi M, Hedayati N. Effect of addiction to computer games on physical and mental health of female and male students of guidance school in city of Isfahan background: This study aimed to investigate the effects of addiction to computer. Addict Health 2009;1:98-104. Available from: http://www.ncbi.nlm.nih.gov/pubmed/24494091
. [Last cited on 2016 Jul 10].
Kim NR, Hwang SS, Choi JS, Kim DJ, Demetrovics Z, Király O, et al.
Characteristics and psychiatric symptoms of internet gaming disorder among adults using self-reported DSM-5 criteria. Psychiatry Investig 2016;13:58-66.
Park HS, Kim SH, Bang SA, Yoon EJ, Cho SS, Kim SE. Altered regional cerebral glucose metabolism in internet game overusers: A 18F-fluorodeoxyglucose positron emission tomography study. CNS Spectr 2010;15:159-66.
Lin X, Dong G, Wang Q, Du X. Abnormal gray matter and white matter volume in 'Internet gaming addicts'. Addict Behav 2015;40:137-43.
Jin C, Zhang T, Cai C, Bi Y, Li Y, Yu D, et al.
Abnormal prefrontal cortex resting state functional connectivity and severity of internet gaming disorder. Brain Imaging Behav 2016;10:719-29.
Yuan K, Cheng P, Dong T, Bi Y, Xing L, Yu D, et al.
Cortical thickness abnormalities in late adolescence with online gaming addiction. PLoS One 2013;8:e53055.
Hong SB, Harrison BJ, Dandash O, Choi EJ, Kim SC, Kim HH, et al.
A selective involvement of putamen functional connectivity in youth with internet gaming disorder. Brain Res 2015;1602:85-95.
Ko CH, Hsieh TJ, Wang PW, Lin WC, Yen CF, Chen CS, et al.
Altered gray matter density and disrupted functional connectivity of the amygdala in adults with Internet gaming disorder. Prog Neuropsychopharmacol Biol Psychiatry 2015;57:185-92.
Wang Y, Yin Y, Sun YW, Zhou Y, Chen X, Ding WN, et al.
Decreased prefrontal lobe interhemispheric functional connectivity in adolescents with internet gaming disorder: A primary study using resting-state FMRI. PLoS One 2015;10:e0118733.
Ko CH, Liu GC, Hsiao S, Yen JY, Yang MJ, Lin WC, et al.
Brain activities associated with gaming urge of online gaming addiction. J Psychiatr Res 2009;43:739-47.
Ko CH, Liu GC, Yen JY, Chen CY, Yen CF, Chen CS. Brain correlates of craving for online gaming under cue exposure in subjects with Internet gaming addiction and in remitted subjects. Addict Biol 2013;18:559-69.
Dong G, DeVito E, Huang J, Du X. Diffusion tensor imaging reveals thalamus and posterior cingulate cortex abnormalities in internet gaming addicts. J Psychiatr Res 2012;46:1212-6.
Lemmens JS, Valkenburg PM, Gentile DA. The Internet gaming disorder scale. Psychol Assess 2015;27:567-82.
Vadlin S, Åslund C, Nilsson KW. Development and content validity of a screening instrument for gaming addiction in adolescents: The Gaming Addiction Identification Test (GAIT). Scand J Psychol 2015;56:458-66.
Vadlin S, Åslund C, Rehn M, Nilsson KW. Psychometric evaluation of the adolescent and parent versions of the Gaming Addiction Identification Test (GAIT). Scand J Psychol 2015;56:726-35.
King DL, Delfabbro PH. The cognitive psychopathology of Internet gaming disorder in adolescence. J Abnorm Child Psychol 2016;44:1635-45.
Sakuma H, Mihara S, Nakayama H, Miura K, Kitayuguchi T, Maezono M, et al.
Treatment with the Self-Discovery Camp (SDiC) improves Internet gaming disorder. Addict Behav 2017;64:357-62.
Park SY, Kim SM, Roh S, Soh MA, Lee SH, Kim H, et al.
The effects of a virtual reality treatment program for online gaming addiction. Comput Methods Programs Biomed 2016;129:99-108.
Han DH, Hwang JW, Renshaw PF. Bupropion sustained release treatment decreases craving for video games and cue-induced brain activity in patients with Internet video game addiction. Exp Clin Psychopharmacol 2010;18:297-304.
King DL, Delfabbro PH. Internet gaming disorder treatment: A review of definitions of diagnosis and treatment outcome. J Clin Psychol 2014;70:942-55.
Nath K, Naskar S, Victor R. A Cross-Sectional Study on the Prevalence, Risk Factors, and Ill Effects of Internet Addiction Among Medical Students in Northeastern India. Prim care companion CNS Disord [Internet]. Physicians Postgraduate Press, Inc.; 2016;18. Available from: http://www.ncbi.nlm.nih.gov/pubmed/27486546
. [Last cited on 2017 Feb 22].
[Table 1], [Table 2], [Table 3], [Table 4]