POMC and major depressive disorder: Corticotropin-releasing factor (CRF) plays a key role in response to stress mediating the neural control of adrenocorticotropic hormone (ACTH) release from pituitary corticotrophs, which in turn regulate cortisol secretion acutely but may lead to the development of stress-related disorders (i.e., anxiety and depression) when exposed to chronic stress [66].