Dr Ran Tao and colleagues have made an important contribution to the scientific literature on compulsive, excessive involvement with internet games such as ‘World of Warcraft’. By examining carefully groups of patients in treatment in his hospital, which specializes in the treatment of this condition, he has produced data on clinical characteristics, frequency among students of similar age and on the clinical course among patients in his part of China. This is indeed helpful to our consideration of whether this condition should be considered a new disorder with unique and consistent characteristics, and thus added to the Diagnostic and Statistical Manual (DSM), currently in revision as DSM-V.
Indeed, the DSM-V Work Group on Substance Related disorders has been considering carefully reports of compulsive behaviors that in some ways resemble the compulsive use of drugs such as ethanol or nicotine. Neuroscience research on addictions has long demonstrated that those drugs taken to excess by humans have in common the activation of the reward system in the brain. Both animal models and human brain imaging research support this finding. Of course, brain reward activation is normal and is involved in healthy motivation. However, activation of reward by drugs is different  and in vulnerable individuals may lead to activation as a conditioned reflex when confronted by drug-associated cues, with subsequent loss of control over behavior. Perhaps non-substance-related behaviors such as gambling or internet gaming could also produce intense reward system activation and lead to compulsive behavior similar to an addiction .
Pathological gambling (DSM-IV) has been the focus of considerable research, including brain imaging studies and clinical trials. There is a proposal by the DSM-V Work Group to move the DSM-IV ‘pathological gambling’ into the category of addictions because of its many similarities to the substance addictions. The name would be changed to ‘gambling disorder’. Dr Ran Tao and colleagues make a strong case for considering compulsive internet use to be grouped similarly with addictions in DSM-V.
It is true that therapeutic approaches learned from the treatment of substance use disorders are being applied to the problem of compulsive internet use, apparently with some success. Adding it to the DSM, however, would be adding a completely new diagnosis and the threshold for adding a diagnosis is very high. The study of possible internet addiction is still at a very early stage. There is a growing literature on the subject, particularly from Asia . Studies similar to the Tao study should be conducted in other parts of the world and patients should be studied longitudinally. What are the short- and long-term treatment success rates? What is the relapse rate after successful treatment? Does the male predominance seen in this part of China exist in other settings? Is there an ethnic or genetic vulnerability factor? What about co-morbidity with other psychiatric disorders? Are there any medications that can be helpful?
No decisions as to the final form of the addiction section in DSM-V have been made. At this time it is likely that ‘gambling disorder’ will be grouped with the drug use disorders, but ‘internet addiction’ will be listed in the Appendix with references to the existing literature, including the excellent study published by Dr Ran Tao and colleagues. The plan for future changes in the DSM is that they would occur as the science develops. If future controlled studies of this problem are conducted by other groups and in other parts of the world, the reports of these studies in the scientific literature will be reviewed. While a process for ongoing modifications of DSM-V has not yet been finalized, it is anticipated that this fifth version of the DSM will be a living document. Thus, in a few years, a version that might be called DSM-V.1 could include an ‘internet addictive disorder’. Whether or not this will occur depends on additional studies in peer-reviewed scientific journals in the mould of the report in this issue by Dr Ran Tao and colleagues.