Altered activity within reward-related neural regions, including the ventral striatum (VS) and medial prefrontal cortex (mPFC), is associated with concurrent problematic substance use. Researchers sought to identify patterns of reward-related neural activity that prospectively predicted changes in alcohol use two years after magnetic resonance imaging (MRI) scanning in a sample of adolescents, and examined whether these patterns differed by sex. In addition, the researchers also tested whether depression symptoms or impulsivity mediated associations between neural activity and future alcohol use.
262 Mexican-origin adolescents (129 male) 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 indicated that different patterns of rewardrelated neural activity predicted future increases in alcohol use for male and female adolescents. In boys, higher ventral striatum activity during reward anticipation and average ventral medial prefrontal cortex activity during reward feedback predicted increases in alcohol use from age 16 to 18; in girls, higher dorsal medial prefrontal cortex activity and blunted ventral striatum activity during reward anticipation predicted increases in alcohol use from age 16 to 18. Depression symptoms or impulsivity did not mediate these associations.
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, the authors comment.
Source: Reward-Related Brain Activity Prospectively Predicts Increases in Alcohol Use in Adolescents. Swartz JR, Weissman DG, Ferrer E, Beard SJ, Fassbender C, Robins RW, Hastings PD, Guyer AEJ Am Acad Child Adolesc Psychiatry. 2019 Jun 4. pii: S0890-8567(19)30388-0.