A Neurodevelopmental Model of Social Threat Sensitivity as a Mechanism Linking Fearful Temperament, Social Anxiety, and Depression in Youth.

Sensitivity to social threat is one form of emotion dysregulation implicated in internalizing psychopathologies, yet its developmental origins and mechanistic role remain insufficiently specified. One of the most reliable, early-emerging predictors of internalizing disorders is extreme fearful temperament, which is characterized by heightened sensitivity to novelty and threat, especially if social in nature. Links between early fearful temperament, social reticence with unfamiliar peers in childhood, and the later emergence of social anxiety disorder are well-established, as is the link between social anxiety and subsequent depression. This narrative review integrates research on altered processing of social threat across units of analysis (behavior, electroencephalography/event-related potential, functional magnetic resonance imaging, self-report) in youth with fearful temperament, anxiety, and depression, as well as the role of social threat sensitivity in shaping these prospective associations. We propose a conceptual model in which hypervigilance to social threat beginning in early childhood promotes social avoidance, which, in turn, heightens sensitivity to signals of negative social feedback from peers. These vulnerabilities may be compounded by normative increases in sensitivity to social threat across adolescence, leading to higher rejection sensitivity, a lower sense of connectedness with peers, and increased risk for the onset of internalizing disorders. We conclude with recommendations for future research, including the need to delineate how these neurobehavioral vulnerabilities unfold in real-world social contexts, improve precision in predicting subtypes of internalizing symptoms, and identify risk and protective factors that alter this trajectory.