Impulsivity facets and substance use initiation: A comparison of two models of impulsivity.

Several types of impulsivity have been linked to various substance use outcomes. The UPPS-P framework has received major focus within the field of substance use research. However, this framework is not without limitation. An alternative framework is the Two-Factor Model of impulsivity, which posits that rash impulsivity and reward drive are the central, if not sufficient, domains of impulsivity. Unfortunately, the extant literature is quite limited in terms of work that have directly compared the UPPS-P framework to the Two-Factor Model of impulsivity, particularly in prospective designs focused on the initiation of common, problematic forms of substance use among adolescents (i.e., alcohol and marijuana use). In the current study, the UPPS-P measures were compared to dedicated measures of the Two-Factor Model of impulsivity in a sample of Chilean adolescents who were lifetime abstainers of alcohol or marijuana use at baseline (N = 541) to predict the initiation of use for these substances at a one-year follow-up. Results showed that the Two-Factor Model had superior predictive utility compared to the UPPS-P measures, and only rash impulsivity and reward drive were significant predictors in a multivariate model that simultaneously considered UPPS-P and Two-Factor Model assessments. Overall, the current findings indicate that the Two-Factor Model should be considered to index risk of substance use initiation to guide prevention efforts and highlight the importance of direct comparisons of alternative measurement and theoretical frameworks of impulsivity within the field of substance use research.