Note. M age = mean age of youth (years). Signs adjacent to paths (+ and −) indicate hypothesized positive and negative associations, respectively. All key mediators and outcome (alternative reinforcement and complementary reinforcement at W1 and W3, substance use at W1, W2, and W4) were regressed on covariates (i.e., youth age, sex, dummy-coded race [White as reference], living situation, family substance use history, and delinquent behaviors).