The ACTH stimulation test before and after clinical recovery from depression

Excessive cortisol secretion after cosyntropin (adrenocorticotropic hormone; ACTH) infusion in some depressed patients has suggested the possibility that the adrenal cortex may have heightened responsiveness to ACTH, and that this may contribute, in part, to activation of the hypothalamic-pituitary-adrenocortical axis. We administered an ACTH test and dexamethasone suppression test (DST) to 32 patients before and after treatment. Maximal cortisol response to ACTH demonstrated a significant decrease after treatment in the subgroup of melancholic/DST nonsuppressors (p = 0.04). When the cumulative cortisol response (CCR) to ACTH was examined, the DST nonsuppressors had a greater CCR decrease than suppressors (p = 0.03), and the melancholics a greater decrease than nonmelancholics (p = 0.02). The melancholic/DST nonsuppressor subgroup had the largest CCR decrease after treatment (p = 0.03), and these patients may represent a group of depressives with altered adrenocortical function that tends to "normalize" with clinical recovery.