Emotional non-acceptance links early life stress and blunted cortisol reactivity to social threat.

Early life stress (ELS) has been recently associated with blunted cortisol reactivity and emotion dysregulation, but no study until now examined whether these characteristics are related. The main goal of this study was to examine the potential mediator role of emotion dysregulation in the relation between ELS and cortisol reactivity to social threat. Only women who were free of psychiatric and endocrine disorders, had regular menstrual cycle and did not use oral contraceptives were selected for this study (N=62). After filling in ELS and multidimensional emotion dysregulation measures, participants underwent the Trier Social Stress Test during which cortisol and autonomic responses were assessed. Most participants (85.5%) reported one or more major stressful events (i.e., physical abuse, sexual abuse, major parental conflicts, death of a family or close friend, severe illness) experienced before age 17. ELS was negatively associated with cortisol reactivity and positively associated with skin conductance level (SCL) reactivity, but it did not influence heart rate and respiratory sinus arrhythmia. In addition, ELS was positively related to emotional non-acceptance (i.e., a tendency to develop secondary emotional responses to one's negative emotions), and the latter was negatively related to cortisol responses and positively related to SCL responses. Bootstrapping analyses indicated that emotional non-acceptance was a significant mediator in the relationships between ELS and both cortisol and SCL responses. Emotional non-acceptance is thus one of the psychological mechanisms underlying blunted cortisol and increased sympathetic reactivity in young healthy volunteers with a history of ELS.