Differential Role of Cannabis Use Motives in Predicting Impairment Across Three Measures.

OBJECTIVE: Previous research has demonstrated the utility of motivational models of cannabis use to predict the frequency of use and associated negative consequences. However, few existing studies have simultaneously investigated a range of motives across different measures of use-related problems, which limit the ability to assess the differential role various motives play. The purpose of the current study was to examine cannabis use motives as predictors of three measures of cannabis use risk.

METHOD: Participants (N = 229) who reported cannabis use within the past 30 days completed the Marijuana Motives Measures, as well as measures of typical smoking behavior and risk: Cannabis Use Disorders Identification Test-R (CUDIT-R; screening measure of hazardous cannabis use), Marijuana Problem Index (MPI; measure of broad psychosocial problems), and cannabis use disorder according to criteria from the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).

RESULTS: Cannabis use motives-particularly coping, enhancement, and conformity-contributed to the prediction of cannabis-related impairment beyond gender and the frequency of recent use. Among the motives scales, coping emerged as the most robust predictor across the three impairment measures and was the only motive to add unique variance to predictions of DSM-5 symptoms. Enhancement and conformity motives were predictive of the screening measure (CUDIT-R scores), and enhancement motives was also predictive of a measure of broad psychosocial problems related to cannabis use (MPI scores).

CONCLUSIONS: The results highlight the differential role various marijuana use motives play across related but distinct measures of impairment.