Amygdalar Activation as a Neurobiological Marker of Differential Sensitivity in the Effects of Family Rearing Experiences on Socioemotional Adjustment in Youths

Abstract Background Substantial heterogeneity exists in how rearing environments influence youths’ socio-emotional outcomes. This heterogeneity, as suggested by the biological sensitivity to context (BSCT) and the differential susceptibility (DST) theories, is associated with emotional reactivity patterns and underlying neural functions. The present study investigated amygdalar reactivity to emotional stimuli as a neural signature that amplified the influence of rearing environments on youths’ socio-emotional outcomes. Methods To increase replicability and generalizability, this investigation included two independent studies that methodologically complemented each other. Study I employed a large, national, and longitudinal dataset (the ABCD study; N=11,875). Study II used a community sample of youths (N=123) with multi-method and multi-reporter assessments. Results In Study I, high left amygdalar reactivity to positive stimuli significantly amplified the impact of parental warmth on youths’ prosocial behaviors. In Study II, left and right amygdala reactivity to positive stimuli significantly intensified the associations between family functioning and youths’ internalizing problems. These findings were consistent with the BSCT/DST hypothesis because significant socio-emotional differences were observed at both negative and positive extremes of rearing environments. Additionally, Study II partially supported the diathesis-stress hypothesis by showing significant differences in youths’ vulnerability to negative family environments. Specifically, left amygdalar response to negative stimuli exacerbated the associations between unbalanced family functioning and heightened internalizing/externalizing symptoms. Left amygdalar reactivity to positive stimuli intensified the link between unbalanced family functioning and elevated externalizing problems. Conclusions Among youths and adolescents, amygdalar emotional reactivity may serve as a biomarker of differential sensitivity to rearing environments.