IGD is categorized as a behavioral addiction similar to pathological gambling, sexual activity, exercise, and shopping3 because these diverse behavioral addiction disorders share a number of clinical features including repetitive behavior despite negative results, a lack of control over urges, and cravings prior to engagement in the behavior4. According to a review by Olsen, non-drug addictions alter neuroplasticity in brain areas associated with reward processing and drug addiction5. The inclusion of behavioral addictions as a new class of disorders was proposed for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), but only Gambling Disorder (GD) was categorized as such6. However, it is suggested in the appendix of the DSM-5 that IGD be further assessed as an addictive condition because it has been associated with depressed mood, anxiety, and aggressiveness as well as with psychiatric disorders such as attention deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD)7–12. Thus, there is a pressing need to elucidate further the neurobiological pathophysiology underlying IGD to better understand this disorder.
