Adrenocortical responsiveness to the ACTH stimulation test in depressed patients and healthy volunteers.

Adrenocortical activation in depression has been postulated to result from overactivity of limbic system-hypothalamic function. However, some studies suggest the possibility that excessive secretion of cortisol might result, in part, from a heightened adrenocortical responsiveness to ACTH. To further examine this possibility, we utilized both the ACTH stimulation test and the overnight dexamethasone suppression test (DST) in 72 patients with major depression and 37 age- and gender-matched healthy volunteers. The melancholic/DST-nonsuppressor group had larger mean peak cortisol and cumulative cortisol responses (CCR) than any of the other patients groups or healthy controls. However, the differences failed to reach statistical significance as a result of a relatively large cortisol response variability. Nevertheless, the present findings are in general agreement with previous reports suggesting the possibility of an enhanced adrenocortical responsiveness to ACTH.