POMC and major depressive disorder: Willard et al. and Michopoulos et al. have previously demonstrated that socially subordinate adult female M. fascicularis subjects more commonly present depression-like behavior and dysregulation of the limbic–HPA axis (e.g., decreased cortisol in response to ACTH and decreased glucocorticoid negative feedback; lower CSF DOPAC and serum PACAP) [39], [40].