Impulsivity Facets, Social Norms, and Co-Use of Alcohol and Cannabis.

Compared to alcohol-only use, co-use of alcohol and cannabis is becoming increasingly more common. Impulsivity and perceived norms are two factors related to increased substance use among young adults, but few studies have examined their role in co-use. The purpose of this study was to examine whether impulsivity facets moderated the associations between perceived norms (descriptive and injunctive) for co-use frequency. Participants were college students who completed an online survey regarding their impulsivity, norms, and co-use behaviors. In the descriptive norms model, findings revealed lack of premeditation was negatively associated with co-use frequency. There was a significant interaction between descriptive norms and lack of perseverance on co-use frequency. In the injunctive norms model, findings revealed that injunctive norms were positively associated with co-use frequency; lack of premeditation was negatively associated with co-use frequency. Perceived norms and some impulsivity facets may serve as risk factors for increased co-use frequency.