Assessing the mediating role of impulsivity between methamphetamine-induced psychotic disorders and increased gambling severity in methamphetamine-dependent individuals.

Pathological gambling (PG) and methamphetamine-induced psychotic disorders (MIPD) both frequently occurs in methamphetamine-dependent individuals. The current study examined whether impulsivity mediated the relationship between MIPD and gambling severity. The sample consisted of 320 pathological gamblers with methamphetamine dependence (mean age 32.6 years, ranging from 15 to 64 years) voluntarily recruited from three rehabilitation centers in Hunan, China. The semistructured clinical interview of DSM-IV-TR Axis I Disorders Patient Edition was used to diagnosis the presence of MIPD and PG by registered psychiatrists. The severity of gambling symptoms was assessed using the global assessment of functioning scale, and the Barratt Impulsiveness Scale-11 provided a measure of impulsivity. Of the sample, 53.4% of participants (n = 171) met diagnostic criteria for MIPD. Individuals with a dual diagnosis of MIPD were associated with higher levels of impulsivity and greater gambling severity. Notably, support for our hypothesized mediation model was found such that impulsivity mediated the association between MIPD and gambling severity. Our findings imply that impulsivity appears to be a transdiagnostic process, which may be targeted in treatment among pathological gamblers with a dual diagnosis of MIPD to reduce gambling behaviors. Limits and future directions for research are discussed.