Co-use of alcohol and cannabis: Do social norms relate to personal use and consequences among college students?

The purpose of the present study was to examine (1) differences in descriptive and injunctive norms for alcohol, cannabis, and co-use, (2) whether descriptive and injunctive norms for alcohol, cannabis, and co-use were associated with co-use frequency, and (3) whether co-use descriptive and injunctive norms were associated with co-use consequences. Participants were 209 college students who were required to have engaged in only alcohol, only cannabis, and co-use in the past year. Participants completed an online survey about their substance use. For Aim 1, participants held the strongest descriptive and injunctive norms for alcohol use. For Aim 2, descriptive norms for co-use were related to greater co-use frequency; injunctive norms were not associated with co-use frequency. For Aim 3, both types of norms were not associated with co-use consequences. In comparison to descriptive norms for alcohol-only and cannabis-only, descriptive norms for co-use were most strongly tied with personal co-use frequency. Findings may inform intervention work focused on college students who engage in co-use by targeting normative perceptions of co-use.