Objective: Relatively little research has evaluated motives for using marijuana based on users' self-reported reasons. This article details the construction and psychometric validation of a new marijuana motives questionnaire. Method: Participants included 346 marijuana-using college students who completed online assessments regarding their motives for, frequency of, and problems associated with their marijuana use. Results: Exploratory and confirmatory factor analysis supported a 12-factor scale, including the following: (1) Enjoyment, (2) Conformity, (3) Coping, (4) Experimentation, (5) Boredom, (6) Alcohol, (7) Celebration, (8) Altered Perception, (9) Social Anxiety, (10) Relative Low Risk, (11) Sleep/Rest, and (12) Availability. Regression results indicated enjoyment, boredom, altered perception, relative low-risk, and sleep/rest were each uniquely associated with greater frequency of use. Experimentation and availability motives were associated with less use. After accounting for use, coping and sleep/rest were associated with significantly more consequences whereas enjoyment was associated with fewer consequences. Additional results comparing the scale to an existing marijuana motives measure indicated comparatively good convergent validity. Conclusions: Emerging adult college students may have several different reasons for using marijuana, which are uniquely related to use and negative consequences. Results are considered in terms of their implications for brief interventions. (J. Stud. Alcohol Drugs 70: 279-287, 2009)
