PROJECT SUMMARY/ABSTRACT Exposure to early childhood adversity is associated with a range of negative health outcomes including increased risk of psychopathology across the lifespan. In particular, those who are exposed to environmental threat (e.g., abuse from caregivers, community violence) are at elevated risk for mental health disorders, particularly depression, that become more prevalent as youth transition to adolescence. Theory and research have tried to account for the variability in outcomes of youth exposed to adversity by identifying mechanisms linking early threat exposure to later functioning. Prominent contemporary models of adversity suggest that exposure to threatening early environments sensitizes neural and psychological systems involved in emotion processing and stress responsivity in ways that promote adaptation while also increasing risk for later emotional hyper-reactivity and psychopathology. However, the majority of research to date has focused on links between sensitivity to emotional cues and risk for psychopathology, neglecting the ways that sensitivity to the environment – particularly the social environment, which becomes more salient during adolescence – may support adaptation among threat-exposed adolescents. Further, research to date has examined concurrent associations between neural activation and psychopathology, neglecting the role of integration across brain networks and associations with trajectories of development over time. The proposed research will provide training in adversity research, neural network modeling, and longitudinal statistical analysis while examining the effect of early threat exposure on neural sensitivity to social-emotional information and subsequent psychosocial outcomes in adolescents. Two main aims guide this research: (1) exploring whether childhood threat exposure predicts heightened neural and behavioral sensitivity to negative and positive social cues; and (2) exploring how this heightened sensitivity interacts with peer experiences to predict changes in depression and social-emotional wellbeing over time. These aims will be addressed in a large longitudinal study of adolescents (expected n = 275) who will complete self-report measures and a social feedback functional magnetic resonance imaging task. Resources that will support this research include access to this rich sample, facilities for neuroimaging and behavioral assessment, and a mentorship team with expertise in adversity science and developmental neuroscience. Findings from this project will enrich theory regarding how youth develop following threat exposure and identify strengths that can be leveraged to prevent psychopathology and support wellbeing among adversity-exposed adolescents.