Relationship between peer norms and substance use among young MSM

Background: Prior studies have demonstrated a link between substance use and sexual risk, and while the effectiveness of peer norms lowering sexual risk has been established; the role of peer norms on substance use is not known among young MSM. Method: As part of the evaluation of a community-level HIV-prevention intervention for young Black and White MSM in Philadelphia, we recruited 282 MSM ages 15 to 29, at venues and through chain referrals. At baseline, Interviewers administered part of the survey, while participants utilized ACASI to complete more sensitive sections. Peer norms were measured with four items on a scale from 1 to 5 (alpha=.71). We assessed addiction using a 9-item scale (alpha=.78). Results: Men who did not use drugs reported stronger peer norms compared to men who used drugs; however, men who only used marijuana were comparable to non-drug users (p < .001). We found similar results for non-bingers compared to binge drinkers (p< .02). Men who scored higher for addiction reported weaker peer norms (p< .001). Younger men and gay-identified men reported stronger peer norms (p< .03 & .02, respectively). Conclusions: Drug users and binge drinkers were significantly more likely to report having peers who used drugs and alcohol. Since men who used marijuana were similar to non-drug users, prevention messages that target young MSM may want to address marijuana separately. Incorporating peer norms into HIV and substance use prevention interventions may be an effective tool to protect young MSM from substance use problems and exposure to HIV.