Amygdala and Subgenual Cingulate Stressor-Evoked Activity Varies Across a Spectrum of Childhood Adversity Severity: Links to Affective and Cardiovascular Outcomes

Background Childhood adversity is linked to psychopathology risk and dysregulated stress reactivity; however, unified underlying neural mechanisms are unclear. A central visceral network, including the bed nucleus of the stria terminalis (BNST), amygdala and subgenual anterior cingulate cortex (sgACC), is implicated in affective processes and proximally controls stress reactivity. We examined relationships among childhood adversity, stressor-evoked neural activity/connectivity and affective and cardiovascular outcomes. Methods Participants were adults (n=97, mean age=27.32, SD=4.02, 57 females) uniformly distributed across physical abuse severity. Childhood adversity was assessed by threat (abuse or traumatic events) and socioeconomic deprivation (SED). Participants performed an fMRI stress task with cardiovascular recordings. Linear/curvilinear regressions were performed with threat and deprivation together as predictors of stressor-evoked activity/connectivity. Neural variables showing significant adversity associations were examined as predictors of affective symptoms/diagnoses or cardiovascular responses. Results Threat and SED displayed opposing curvilinear relationships with stressor-evoked amygdala and sgACC activity, respectively: at low and high adversity, amygdala reactivity was greater, whereas sgACC reactivity was blunted. Greater SED was associated with weaker BNST-sgACC connectivity. Blunted amygdala reactivity and lower sgACC reactivity were associated with greater post-traumatic stress symptoms. Affective diagnoses peaked at near-zero BNST-sgACC connectivity. Greater amygdala reactivity was associated with blunted diastolic blood pressure reactivity and recovery. Conclusions The curvilinear relationships suggest adversity-related vulnerability thresholds. Blunted amygdala, lower sgACC reactivity and weaker BNST-sgACC connectivity may confer affective risk, whereas heightened amygdala reactivity may confer cardiovascular risk. Our findings support a central visceral network pathway by which childhood adversity may contribute to affective and cardiovascular health.