Integrating the pattern of negative emotion processing and acute stress response with childhood stress among healthy young adults

Background Childhood abuse might impair corticolimbic brain regions, which play a crucial role in emotion processing and the acute stress response. Yet few has explored the relationship between childhood stress, emotion processing and acute stress reactivity despite the overlapping brain regions of the last two. Here, we examine the relationships between distinct dimensions of childhood adversity (i.e., deprivation and threat) and emotion processing as well as acute stress response. Furthermore, we explore whether emotion processing (particularly threatening information), which might be particularly relevant for adaptive stress responding among individuals with experience of childhood abuse, mediates the relationship between childhood stress and acute stress response. Method Fifty-one young adults completed a free-viewing task to evaluate neural response to negative stimuli measured by late positive potential (LPP) of ERPs (Event-related potentials). In a separate day, heart rate and salivary cortisol were collected during a social-evaluative stress challenge (i.e., TSST, Trier Social Stress Test). After the TSST, childhood trauma questionnaire was measured to indicate the level of abuse (as a proxy of threat) and neglect (as a proxy of deprivation) dimensions. Results Higher level of childhood abuse (but not neglect) was distinctly related to smaller LPP amplitudes to negative stimuli, as well as smaller heart rate reactivity to acute stress. For these participants, smaller LPP amplitudes linked with smaller heart rate reactivity to acute stress. Furthermore, decreased LPP amplitudes to negative stimuli mediated the relationship between higher level of childhood abuse and blunted heart rate reactivity to stress. Conclusions Consistent with the dimensional model of childhood stress, our study showed that childhood abuse is distinctly associated with neural as well as physiological response to threat. Furthermore, the blunted neural response to negative stimuli might be the underlying mechanism in which childhood abuse leads to blunted acute stress response. Considering that all the participants are healthy in the present study, the blunted processing of negative stimuli might rather reflect adaptation instead of vulnerability, in order to prevent stress overshooting in the face of frequent early-life threatening experiences.