Preservation of hypothalamic-pituitary-adrenal axis fast-feedback responses in depression
Depression is associated with overactivity of the hypothalamic-pituitary-adrenal (HPA) axis, which may be attributable to defective negative feedback. Fast feedback is the earliest phase of this, and has previously been suggested to be abnormal. A total of 30 physically healthy volunteers, 15 patients with DSM-III-R major depression and an age- and sex-matched control group received a standardized challenge of hydrocortisone (5 μg kg-1 min-1) or placebo over a period of 1 h. ACTH1-39 responses to hydrocortisone challenge did not differ significantly between healthy volunteers and patients with major depression. The fast-feedback response to hydrocortisone challenge is preserved in major depression when ACTH is measured directly.