The Relationship Between Risk Factors and Alcohol and Marijuana Use Outcomes Among Concurrent Users: A Comprehensive Examination of Protective Behavioral Strategies.

OBJECTIVE: Among college samples, both alcohol and marijuana protective behavioral strategies (PBS) have been shown to mediate the effects of known risk factors (i.e., sex, age at substance use onset, college substance use beliefs, substance use motives, and impulsivity-like traits) on alcohol and marijuana outcomes. However, it is unknown whether PBS use would operate similarly for both substances among concurrent users. The present study examined which risk factors relate to alcohol/marijuana outcomes via alcohol/marijuana PBS use among a large group of concurrent alcohol/marijuana users.

METHOD: Participants were college students who consumed both alcohol and marijuana at least 1 day in the previous month (n = 2,034; 69.08% female).

RESULTS: Across both substances, PBS use significantly mediated the effects of sex (women reported higher PBS use), age at first use (having an older age at first use was associated with more PBS use), and college substance use beliefs (higher beliefs was associated with lower PBS use). Unique to alcohol outcomes, alcohol PBS use significantly mediated the effects of negative urgency, social motives, and enhancement motives (all associated with lower PBS use). Unique to marijuana outcomes, marijuana PBS use mediated the effects of coping, expansion (both associated with lower PBS use), and conformity motives (associated with more PBS use).

CONCLUSIONS: Our results suggest that PBS for both alcohol and marijuana can help explain why some risk factors are associated with alcohol/marijuana outcomes. Taken together, PBS use seems to be an important intervention target for alcohol/marijuana concurrent users.