The effect of mortality salience and early-life maternal care on neuroendocrine, autonomic, and psychological stress responses

Adverse early-life experiences alter the regulation of major stress systems such as the hypothalamic-pituitary-adrenal (HPA) axis. Low early-life maternal care (MC) has repeatedly been related to blunted cortisol responses to stress. Likewise, an acutely increased awareness of mortality (mortality salience, MS) also has been shown to blunt cortisol responses. In the current study we investigated the effects of early-life MC and a potential interaction with MS on HPA axis responsivity, as well as autonomic and subjective stress responses. Seventy-three women (Mage=21.56, SDage=2.85) with self-reported low (n=30) or high (n=43) early-life MC, underwent the Trier Social Stress Test for groups. Prior to stressor exposure they were asked to briefly reflect either on death (mortality condition, n=38) or sleep (control condition, n=35). Salivary cortisol and alpha amylase, heart rate variability and subjective stress levels were assessed throughout the experiment. Multilevel mixed models confirmed an effect of MC on stress system regulation, indicated by blunted cortisol stress responses and overall reduced heart rate variability in low compared with high MC individuals. Moreover, we found an interaction between MS and MC concerning subjective stress levels and changes in heart rate variability. These findings demonstrate the impact of low early-life MC and the potential role of acute mortality primes on the regulation of stress systems in healthy women. Results further imply a superiority of multisystemic approaches to capture and investigate the extensive consequences of exposure to early-life adversity.