These findings may also be attributable to the heterogeneity of the AUD patient population. A recent study argued that AUD is a heterogeneous disorder because it is associated with a number of sub-phenotypes that each have a unique profile of drinking patterns, motivations for drinking, and neurobiological underpinnings57. Additionally, the relative youth of the AUD patients in the present study may have also influenced the results. Age is an important factor when determining structural brain damage in AUD patients and most previous studies investigating this population have assessed middle-aged participants (see Bühler and Mann58 for a review). Because the mean age of the AUD patients in the present study was younger than 30 years, the AUD group may have not included a sufficient number of chronic patients that engaged in long-term alcohol consumption. The present study is also limited in that all participants were asked to abstain from alcohol use for at least 2 weeks prior to participation in this study whereas playing Internet games and Internet usage were not restricted. It is possible that the brain dysfunction of the
