Indicated Prevention for College Student Marijuana Use: A Randomized Controlled Trial

Objective: Marijuana is the most frequently reported illicit substance used on college campuses. Despite the prevalence, few published intervention studies have focused specifically on addressing high-risk marijuana use on college campuses. The present study evaluated the efficacy of an in-person brief motivational enhancement intervention for reducing marijuana use and related consequences among frequently using college students. Method: Participants included 212 college students from 2 campuses who reported frequent marijuana use (i.e., using marijuana at least 5 times in the past month). Participants completed Web-based screening and baseline assessments and upon completion of the baseline survey were randomized to either an in-person brief intervention or an assessment control group. Follow-up assessments were completed approximately 3 and 6 months post-baseline. Marijuana use was measured by number of days used in the past 30 days, typical number of joints used in a typical week in the last 60 days, and marijuana-related consequences. Results: Results indicated significant intervention effects on number of joints smoked in a typical week and a trend toward fewer marijuana-related consequences compared with the control group at 3-month follow-up. Conclusion: This study provides preliminary data on short-term effects of a focused marijuana intervention for college students at reducing marijuana use during the academic quarter.