A Review of the Effects of Prolonged Exposure to Cortisol on the Regulation of the HPA Axis: Implications for the Development and Maintenance of Posttraumatic Stress Disorder

Abstract

The present review examines the extant literature in both human and animal experiments of the stress response. Specifically, this paper aims to demonstrate that the prolonged release, and subsequent higher basal levels of cortisol results in altered functioning of the regulatory systems that modulate the hypothalamic-pituitary-adrenal (HPA) axis. Furthermore, the intent is to show that these alterations in neural circuitry and neuroendocrines play a substantial role in the development and maintenance of posttraumatic stress disorder (PTSD). A review of the literature was conducted and summarized according to the three major regulatory systems that interact to facilitate the functioning of the HPA axis (i.e., hippocampus, amygdala, and prefrontal cortex). Finally, the author integrates the findings and provides a theoretical rationale for the development and maintenance of PTSD. Discussions of limitations and future directions are offered throughout.