Amygdala reactivity to social stress in young adults: A scoping review of neuroimaging studies.

Introduction: Social stress substantially influences emotional and cognitive functioning and is a key contributor to vulnerability for stress-related psychopathology in young adults. The amygdala plays a central role in mediating neural responses to socially evaluative stressors. Although prior neuroimaging studies have examined amygdala reactivity under social stress, findings remain heterogeneous, partly due to individual and methodological variability. Clarifying these patterns is essential for advancing neurobiological models of stress vulnerability. Methods: Following PRISMA-ScR guidelines, PubMed, ScienceDirect, Google Scholar, and BioRxiv were searched for studies published between 2018 and 2024. Eligible studies included healthy participants aged 17-35 and employed validated social stress paradigms. Functional magnetic resonance imaging (fMRI) studies formed the primary focus, with electroencephalography (EEG) studies included when they provided complementary temporal insights into stress-related neural dynamics. Data extraction captured key study characteristics, imaging approaches, stress paradigms, and individual difference variables. Results: Thirteen studies met inclusion criteria. Most fMRI studies reported increased amygdala reactivity during socially evaluative stress. Functional and effective connectivity analyses frequently demonstrated reduced coupling between the amygdala and prefrontal regulatory regions, consistent with impaired top-down emotional control. Individual factors, including sex, genetic variation, resilience, and neurochemical profiles, contributed to variability in neural responses. EEG findings provided complementary evidence of stress-related alterations in oscillatory dynamics associated with threat processing and regulatory processes. Conclusion: Social stress in young adults is commonly associated with heightened amygdala reactivity and altered amygdala-prefrontal connectivity, with substantial interindividual variability. These findings support a shift toward more individualized neurobiological models of stress processing and highlight the importance of methodological standardization and multimodal neuroimaging in future research.