This study tested a model of marijuana use, problems, and motivation and barriers to change among a sample of 422 undergraduate students ages 18-25 (M=19.68, SD=1.60) who used marijuana at least once in the past 6 months. We tested a structural equation model (SEM) with use motives (i.e., coping, enhancement, and expansion), perceived use utility, and gender as exogenous variables predicting ma...