Neural Reactivity to Social Reward Moderates the Association Between Social Media Use and Momentary Positive Affect in Adolescents.

Peer relationships take on increasing importance during adolescence, and there has been considerable debate about the effects of social media use on adolescent emotional health. Little work has examined individual differences in brain function that might impact these associations. In this study, we examined the reward positivity (RewP) to social and monetary reward as a moderator of the relation between social media use and concurrent momentary affect in adolescents. Participants were 145 adolescents aged 14-17 ( = 15.23;  = 1.08; 64.1% female; 71.7% White) at varying risk for depression (47 high-risk based on maternal depression history, 50 low-risk, 48 currently depressed). Measures of social media use, positive affect (PA), and negative affect (NA) were obtained through ecological momentary assessment. In a laboratory session, adolescents completed a computerized peer feedback task and a monetary reward task to elicit the RewP to social and monetary reward feedback. Multilevel models indicated that social media use and a smaller RewP to monetary rewards were associated with lower PA. However, social (but not monetary) reward responsiveness moderated the effect of social media use on momentary PA, such that social media use was associated with lower PA for adolescents with a relatively blunted RewP to peer acceptance, but not for those with an enhanced social RewP. Exploratory analyses indicated that this moderation effect was specific to female adolescents. The results highlight neural reactivity to social reward as a potential factor contributing to variability in the effect of social media use on affective health.