Abstract
INTRODUCTION: Methamphetamine (MA) users report higher levels of impulsivity relative to healthy controls, which may either result from, or precede, their substance use. Further, there is evidence that female MA users may be more impulsive than male MA users prior to MA use. Thus, the goal of the current study was to determine whether different subtraits of self-reported impulsivity are significantly related to age at first MA use, controlling for total years of MA use. METHODS: A community sample of MA users was recruited for this study (N=157; 113 males, 44 females). The Barratt Impulsiveness Scale (BIS-11) was used to assess self-reported impulsivity on three subscales (Attentional, Motor, Non-planning). Age at first MA use served as the dependent variable in a series of multiple regression models with BIS-11 subscales, sex, and their interaction as independent variables, controlling for total years of MA use. RESULTS: Attentional and Motor impulsivity were significantly related to age at first MA use when controlling for total years of MA use (Attentional: p=0.008; Motor: p=0.003). CONCLUSIONS: Individuals who reported higher Attentional and Motor impulsivity started using MA at an earlier age, which could suggest that impulsivity levels may be an important marker of vulnerability towards MA use. These findings indicate that prevention efforts may be targeted towards individuals who report high levels of Attentional and Motor impulsivity, as they may be at greatest risk for earlier initiation of MA use.