Stimulation of the pituitary-adrenal axis with arginine vasopressin in patients with depression.

The ACTH response to arginine vasopressin was the same in patients with depression while cortisol response was significantly greater in patients with depression when compared to the control population. These findings are consistent with the hypothesis that vasopressin corticotroph receptors are not downregulated in depression and that there is increased adrenal responsiveness in patients with depression to endogenous ACTH.