LAUSR

OBJECTIVE Altered activity within reward-related neural regions, including the ventral striatum (VS) and medial prefrontal cortex (mPFC), is associated with concurrent problematic substance use. The aims of the present study were to (a) identify patterns of reward-related neural activity that prospectively predict changes in alcohol use two years after magnetic resonance imaging (MRI) scanning in a sample of adolescents, and (b) examine whether these patterns differ by sex. We also tested whether depression symptoms or impulsivity mediated associations between neural activity and future alcohol use. METHOD Participants were 262 Mexican-origin adolescents (129 male) who completed the Monetary Incentive Delay task during an fMRI scan at age 16. Participants reported on their alcohol use at ages 16 and 18. RESULTS Results indicated that different patterns of reward-related neural activity predicted future increases in alcohol use for male and female adolescents. In boys, higher VS activity during reward anticipation and average ventral mPFC activity during reward feedback predicted increases in alcohol use from age 16 to 18; in girls, higher dorsal mPFC activity and blunted VS activity during reward anticipation predicted increases in alcohol use from age 16 to 18. Depression symptoms or impulsivity did not mediate these associations. CONCLUSION The results suggest that different pathways of risk may lead to problematic alcohol use for adolescent boys and girls. These sex differences in neural risk pathways have important implications for prevention and intervention approaches targeting Mexican-origin youth.