Objective: The authors tested the hypothesis that patients with major depression have a defect in the mechanism by which cortisol exerts negative feedback on the hypothalamic-pituitary-adrenal (HPA) axis during the HPA axis quiescent period.
Method: Twenty-nine patients with major depression and 25 healthy comparison subjects were randomly assigned to administration of 15 mg cortisol or placebo infused over 2 hours beginning at 7:00 p.m. Cortisol and ACTH levels were measured at baseline and every 30 minutes from 7:30 p.m. to 11:00 p.m.
Results: Differences between the patients and the comparison subjects in the ACTH response to the cortisol infusion, relative to the ACTH response to placebo, were not found.
Conclusions: The results provide some evidence that patients with major depression do not have an abnormality of cortisol feedback during the HPA axis quiescent period.