Cannabis and alcohol use are pervasive among college students. Simultaneous alcohol and cannabis (commonly referred to as simultaneous alcohol and marijuana [SAM]) use (i.e., effects overlap) is more prevalent than concurrent alcohol and cannabis (commonly referred to as concurrent alcohol and marijuana [CAM]) use (i.e., effects do not overlap). Consequences of SAM use are often greater than CAM or single substance use. Research has explored cognitions (motives, expectancies) and contexts (environmental, social) as predictors of...