Marijuana-related perceptions as mediators of the association between trait impulsivity and marijuana outcomes

RHEINHARDT, M. A.; PRINCE, M. A.; PILATTI, ANGELINA; BRAVO, ADRIAN J.; CROSS-CULTURAL ADDICTIONS STUDY TEAM

Congreso; 3rd Annual Scientific Meeting of Research Society on Marijuana; 2019

Background: Previous research has found that normative perceptions (descriptive norms, injunctive norms, and college-related alcohol beliefs) mediate the association between more distal antecedents (i.e., personality traits, including impulsivity) and alcohol outcomes. The purpose of this study is to examine these associations for marijuana outcomes through examining the effect of trait impulsivity on marijuana outcomes via descriptive norms, injunctive norms, and college-related marijuana beliefs. In addition, we sought to test the structural invariance of the model across countries and sex. Method: College students from five countries (U.S., Argentina, Uruguay, Spain, and the Netherlands) completed an online survey as part of a broader study focused on mental health, personality traits, and marijuana use behaviors. Only data from students that reported past month (i.e., past 30-day) marijuana use (n=1,175; 62.9% females) were included in the final analysis from each country (U.S., n=698; Argentina, n=153; Spain, n=178; Uruguay, n=79; Netherlands, n=67). A comprehensive saturated mediation path model was conducted such that double-mediated paths were examined for each impulsivity-related trait and perceived norms. We examined the total, indirect and direct effects of each predictor variable on marijuana outcomes using bias-corrected bootstrapped estimates. In order to test whether our mediation model was culturally-specific or culturally-universal, we conducted χ2 difference tests comparing a freely estimated multi-group model to a constrained multi-group model (i.e., constraining the paths of the mediation model) to determine whether constraining the paths to be equivalent across countries and sex resulted in a worse fitting model. Results: The present results indicate that marijuana-related norms mediate impulsivity-marijuana outcomes associations. Additionally, we found unique significant mediations, via particular perceived norms (specifically injunctive norms), involving specific impulsivity-facets and marijuana outcomes. Further, our findings supported the robust role of college marijuana beliefs as a proximal mediator of personality-marijuana outcomes associations and indicate that this role is still significant when examining the multifaceted nature of impulsivity. Finally, this mediational model was found to be invariant across sex and across different countries/cultures. Discussion: Based on results from the path analysis, impulsivity-like traits, and normative perceptions work in concert to result in marijuana use, which in turn portends risk for marijuana-related consequences. Negative urgency had a robust positive association with marijuana-related consequences, which suggests that intervention and prevention efforts should focus on targeting negative urgency specifically, regardless of cultural background. Of all normative perceptions measured, the strongest and most robust effects were found for perceptions about marijuana use as being part of the college experience. College administrators and other stakeholders could work together with clinicians and public health experts to develop social norms campaigns targeting this perception. Changing the perception that marijuana use is central to the college experience may be an efficient way to reduce marijuana use and related consequences on a large scale.