ment, and a treatment system has been set up. Reports of treatment of this condition have
appeared in medical journals, mostly from A sian countries and some in the United States.
The DSM-5 work group reviewed more than 240 articles and found some behavioral
similarities of Internet gaming  to gambling disorder and to substance use disorders. The
literature suffers, howeve r, from lack of a standard defini tion from which to derive prev-
alence data. An understanding of the natural histories of cases, with or without treatment,
is also missing. The literature does describe many underlying similarities to substance ad-
dictions, including aspects of tolerance, withdr awal, repeated unsuccessful attempts to cut
back or quit, and impairment in normal func tioning. Further, the seemingly high preva-
lence rates, both in Asian countries and, to a lesser extent, in the West, justified inclusion of
this disorder in Section III of DSM-5.
Internet gaming disorder has significant public health importance, and additional re-
search may eventually lead to evidence that Internet gaming disorder (also commonly re-
ferred to as Internet use disorder,  Internet addiction,  or gaming addiction ) has merit as an
independent disorder. As with gambling disord er, there should be epidemiological stud-
ies to determine prevalence, c linical course, possible geneti c influence, and potential bio-
logical factors based on, for example, brain imaging data. 
Internet gaming disorder is a pattern of exce ssive and prolonged Inte rnet gaming that re-
sults in a cluster of cognitive and behavioral symptoms, including progressive loss of control
over gaming, tolerance, and withdrawal sy mptoms, analogous to the symptoms of sub-
stance use disorders. As with substance-related disorders, individuals with Internet gaming