CRH and major depressive disorder: Non-suppression of cortisol is associated with depression [36], which is associated with excessive secretion of corticotropin releasing factor (CRF): CRF are believed to mediate sleep and appetite disturbances, hypoesthesia and psychomotor changes [37], while responsiveness of adrenocorticotropic hormone, cortisol and dehydroepiandrosterone sulfate to CRF increased responsiveness to CRF are considered to be associated with aging [38].