Gambling disorder and substance-related disorders: Similarities and differences

Gambling disorder (GD) has important similarities with substance use disorders (SUDs) in terms of both diagnostic criteria and underlying mechanisms of action. With regard to diagnostic criteria, only craving is not present as a formal criterion in DSM-5 GD, and chasing losses is not present in SUDs. All other major diagnostic criteria such as loss of control over gambling, tolerance, withdrawal, and negative consequences due to gambling overlap with those of SUD. With regard to underlying mechanisms and vulnerability factors, higher impulsivity, abnormalities in decision-making, deficient executive functions, and related fronto-striatal brain circuitry abnormalities are related to the development and course of both SUD and GD. However, there are also differences between GD and SUD. In gambling, cognitive factors such as risk-taking and decision-making are intrinsically related to the addictive behavior itself, whereas in SUD these effects can also be associated with the pharmacological effect or the neurotoxicity related to (chronic) substance use. Moreover misperceptions with regard to gambling, the experience and interpretation of near misses, and the processing of (potential) rewards and losses influence the experience of gambling, which is not true for SUD. Importantly, these aspects also differ between disordered gamblers and non-problematic gamblers and are thus unique for GD and consitute a risk for relapse. Both shared and unique mechanisms are relevant as targets for the treatment of GD. This chapter concludes with a discussion on novel treatment methods that target some of the working mechanisms shared by GD and SUDs.