Marijuana use, motives, and change intentions in adolescents.

Research typically focuses on motives to use or abstain from marijuana (MJ) in isolation; few studies have integrated both constructs in models of MJ use decision making. We expand the existing literature by integrating these motives in cognitive models of use and cessation in adolescents. We expected use motives to account for past use and intentions for future use, and for motives to abstain to dominate models explaining intention, desire, and self-efficacy for quitting. Adolescent MJ users (N = 162) reported their use and abstinence motives as well as their use and cessation behavior via online survey conducted in high schools. Past use was related to high conformity and low coping, while past cessation attempts were related to high enhancement motives. Intentions to use were related to low negative consequences and conformity, and high enhancement and expansion motives to use. Quitting intention was related to social motives to use, as was quitting self-efficacy. Self-efficacy was also related to high personal/peer beliefs motives to abstain. While past MJ use and intended future use were almost exclusively accounted for by use motives, both motives to use and abstain impacted self-reported cognitions associated with cessation in this sample of adolescent MJ users.