Drinking for a reason: how drinking motives shape alcohol use across the lifespan

Alcohol is one of the most used substances globally, but motives for use vary and may shift across the lifespan. Drinking motives are commonly divided between 1) coping: to alleviate negative affect, 2) enhancement: because the feeling is nice, 3) social: to enhance social interactions, and 4) conformity: to fit in a group; and measured using the Drinking Motives Questionnaire Revised (DMQ-R). Given that social expectations and the neurological processes underlying alcohol use do not follow linear trajectories, the present study investigates how motives for alcohol use and their associations with use change across the lifespan without assuming linearity. Alcohol users (N = 908; 16-81yrs) completed the DMQ-R and measures of alcohol use severity. Generalized additive models assessed non-linear associations between, drinking motives, age, and alcohol use severity, including age-by-motive interactions to assess changes across age. Positive non-linear associations between each of the DMQ subscales and alcohol use severity were observed. Inverted U-shaped non-linear associations were found between age and coping and to a lesser extent with conformity, and negative, near-linear associations between age, and social and enhancement motives. The associations between motives and alcohol use severity followed non-linear age-sensitive trajectories: across age, coping and enhancement motives consistently predicted alcohol use severity, while social and conformity motives were predictive only in younger individuals. Our findings highlight the potential of a non-linear approach, showing that coping and enhancement motives are most consistently linked to alcohol use severity, their predictive value remains stable across the lifespan, despite an overall decrease in motive endorsement.