Comparing Behavioral Economic and Internalizing Symptom Predictors of Drinking Trajectories Over 3 Years During Emerging Adulthood

Behavioral economics highlights external influences on alcohol's reinforcing value and suggests life transitions in the mid-to-late 20s may increase costs of drinking, contributing to developmentally mediated drinking reductions among emerging adults. However, higher value for alcohol and fewer substance-free alternatives are theorized to predict persistent risky drinking. The current study compared behavioral economic indices of alcohol value with internalizing symptoms (e.g., anxiety, depression), an established correlate of drinking, as predictors of trajectories of heavy drinking days (HDDs) and alcohol problems among emerging adults. Participants (N = 495, 61.8% female) aged 21.5-25 years at enrollment who reported recent drinking (M_HDD = 1.58) completed questionnaires every 4 months for 3 years about alcohol consumption and problems, internalizing symptoms, alcohol and substance-free rewards, and demographics. HDD and alcohol-related problems were characterized with latent growth curve models. Baseline predictors were regressed onto alcohol growth curves. Both HDD and alcohol-related problems demonstrated quadratic reductions over time. Adjusting for demographics, demand intensity (consumption at zero price) and demand elasticity (sensitivity to changes in cost) were significantly associated with the HDD slope. Demand elasticity, internalizing symptoms, and environmental reward were significantly associated with the alcohol problems slope; lower elasticity and environmental reward scores were associated with accelerated early declines followed by deceleration of change in alcohol problems near the study's end. Results suggest that elevated alcohol reward value, limited access to substance-free rewards, and internalizing symptoms confer persistent drinking risk, and that demand elasticity is a robust unique predictor of these outcomes. (PsycInfo Database Record (c) 2025 APA, all rights reserved).