Regulation of ACTH and cortisol in depression

Disturbances of hypothalamic-pituitary-adrenal regulation are frequently observed in a subgroup of patients suffering from major depression. The mechanism of hypothesized pituitary and hypothalamic involvement in this dysregulation remains relatively uncharacterized. In this paper we investigated the response of adrenocorticotropin (ACTH), as well as cortisol, to dexamethasone inhibition and characterized the dynamic response of ACTH to a one-hour infusion of cortisol in normal subjects and patients suffering from depression. A paradoxical increase in ACTH in response to cortisol is noted in one patient.