Characterizing Reward Function During Social Feedback:  Associations with Anhedonia in Socially Anxious Adolescents

The present study aimed to: (1) Characterize markers of reward sensitivity during periods of social stress using a well validated social feedback paradigm; (2) Evaluate clinical relations between reward markers and anhedonia; and (3) Investigate if elevated levels of baseline prior exposure to stress (i.e., peer victimization) are associated with the degree of ventral striatum suppression and anhedonia symptoms in a social stress context. A total of 29 adolescents between the ages of 13 and 17 years old (Mage = 15.31; SD = 1.51; 55.2% cisgender girls) participated in the present study. Participants were asked to complete a semi-structured interview; fill out self-report questionnaires regarding social anxiety, stress, depression, and anhedonia; and complete a magnetic resonance imaging scan while playing the Island Getaway task. Ventral striatum (VS) BOLD signal activation estimates were then extracted during discrete phases of the game (e.g., anticipation of social feedback and outcome of social feedback) and statistically compared within-subjects via paired samples t-tests and correlated to social anxiety measures. Additionally, regression analyses assessed the effect of VS activation on anhedonia as well as the associative effect of peer victimization on VS activation and anhedonia. Results revealed that when in the presence of social stress (defined as the potential for negative feedback), socially anxious adolescents demonstrated significantly suppressed VS activation relative to baseline when anticipating feedback. Additionally, results indicated that the degree of reduced VS activation during anticipation was correlated to total changes in anhedonia severity across the task. Lastly, results demonstrated that overt peer victimization is a significant predictor of suppressed VS activation during anticipation of social feedback, but not during social outcomes. Taken together, these results identify potentially novel mechanisms associated with anhedonia and blunted reward processing in socially anxious youth that could be improved via interventions that target positive-valence systems.