Validating a five-factor marijuana motives measure: Relations with use, problems, and alcohol motives.

This study adapted and extended M. L. Cooper's (1994) Drinking Motives Measure to examine marijuana motives among 299 college students. An exploratory factor analysis supported the hypothesized 5-factor marijuana motives model, resulting in enhancement, conformity, expansion, coping, and social motives. Analyses supported the internal consistency and concurrent validity of the 5 marijuana motives. Marijuana motives were significant predictors of marijuana use and added to the prediction of use-related problems above and beyond the contribution of lifetime use. Motives and gender interacted in predicting use and use-related problems. Parallel regression analyses revealed that marijuana and alcohol motives predicted comparable amounts of variance in use and use-related problems. However, different patterns of relations emerged across drugs, supporting the discriminant validity of the marijuana and alcohol motives. Young adults use alcohol and marijuana more often than any other abusable drug. According to the Monitoring the Future study (Johnston, O'Malley, & Bachman, 1994), 94% of adults between the ages of 18 and 29 years have used alcohol in their lifetimes, and 56% have used marijuana. As for recent use, 87% drank alcohol in the last year, and 25% used marijuana. Increases in abuse of both alcohol and marijuana have been observed in recent years (National Institute on Drug Abuse NIDA 1996). Also troubling is evidence that the perceived risk of marijuana use has recently decreased among young adults (NIDA, 1996). In light of these trends, increased attention to psychological factors influencing use of these drugs is clearly warranted.