The Hypothalamus-Pituitary-Adrenal Axis and Eating Disorders

The hypothalamic-pituitary-adrenal (HPA) axis is the main component of the endogenous stress response system which regulates the bodily response to real or perceived environmental stressors threatening homeostasis. Several theoretical models have been developed to conceptualize the link between stress and eating behavior, so the HPA axis activity has been widely investigated in people with eating disorders. In patients with eating disorders, both increased and decreased HPA axis activity has been reported. The contradictory findings can be due in part to the heterogeneity of methodologies used across studies. Reduced caloric intake and weight loss, as well as binge-purging behaviors, are associated with an increased activity of HPA axis. However, when considering the occurrence of early adverse experiences, which are associated with impairment of HPA axis functioning, the findings are less clear-cut. Thus, it is important to remember that the mechanisms connecting stress and eating disorders are complex and multi-layered. It is important to recognize the variables that can contribute to these results in order to build formulations and develop precise and targeted treatments.