POMC and psychiatric disorder: With respect to the mechanism responsible for this outcome, we speculate that various stresses and concomitant psychiatric disorders activate the hypothalamic–pituitary–adrenal (HPA) axis to release arginine vasopressin and corticotropin-releasing hormone (CRH) that mediate the secretion of adrenocorticotropic hormone (ACTH) from the anterior pituitary gland, and ACTH in turn mediates the secretion of glucocorticoids from the adrenal cortex (26, 27).