Early-life adversity and regulation of the stress response system : The role of metabolic and psychological interventions
Year: 2023
Type: dissertation
Abstract: Early-life adversity (ELA) has a plethora of harmful consequences for individuals and societies worldwide. It impairs the development and lifelong health of individuals, and is thus linked to an increased risk for adult mental and physical disorders. A central role in this relation is attributed to the body’s stress response, mediated by the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis. ELA is particularly associated with dysregulated, mainly blunted HPA axis responses to stress (i.e., a hyporesponsivity). Possible underlying mechanisms include biological changes (e.g., dysfunction of the HPA axis) and/or psychological changes (e.g., altered stress perception). These pathways are still insufficiently understood, but of great relevance for the development of effective, clinical treatment approaches after ELA. The objective of this thesis was thus (1) to confirm the link between adult HPA axis hyporesponsivity to stress and low early-life maternal care (MC), as one form of ELA, and (2) to extend current knowledge regarding the underlying mechanisms. To this end, I used a set of experimental interventions that affect HPA axis stress responses primarily through biological or psychological pathways, and examined their effects in individuals with varying experiences of received early-life care. Across three projects, I evaluated the role of self-reported MC in young healthy females. In addition, the effect of a metabolic intervention, i.e., glucose ingestion (project 1), and consecutively the impact of two psychological interventions, i.e., mortality salience (project 2) or adaptive cognitive reappraisal (project 3), was examined. Following the interventions, all participants underwent a psychosocial stress test. The primary outcome measure was HPA axis stress responsivity, besides secondary autonomic and subjective-emotional parameters. In project 1, glucose versus water ingestion increased cortisol stress responses, independent of the extent of early-life MC. In project 2, low versus high early-life MC was related to reduced cortisol stress responses; mortality salience did not affect cortisol responses. In the final project 3, focusing on sensory impressions versus positively reappraising a stressful situation was related to higher cortisol stress responses in low MC individuals. Across the studies, there was further evidence for effects of early-life MC on autonomic and subjective-emotional (re-)activity. In sum, the current thesis provides partial support for a link between low early-life MC and HPA axis hyporesponsivity to stress in young healthy females. The findings also indicate a benefit of multisystemic approaches to fully grasp the impact of ELA on the various components of the stress response system. From a mechanistic view, psychological changes in the context of stress and emotional regulation may play a role in linking ELA with HPA axis hyporesponsiveness. This suggests a promising role of psychological interventions in treating the manifold consequences of ELA, including dysregulation of the vital stress response.
Source: KOPS (University of Konstanz)
Author: Bentele, Ulrike U.
Language: English
Subfield: Behavioral Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7135337854