The dexamethasone suppression and metyrapone tests in depression.

The dexamethasone suppression test (DST) and the metyrapone test (MT), a useful and reliable procedure for assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis, were performed in 28 patients suffering from major depressive illness with melancholia. The relationship between the DST and MT appeared to be complex. Patients who failed to suppress cortisol secretion after dexamethasone administration had higher postmetyrapone cortexolone levels and cortexolone/cortisol ratios than suppressors. However, there was a wide range of metyrapone responses in patients exhibiting abnormal DST results. This suggests that failure of adequate suppression after 1 mg of dexamethasone in depressed patients does not necessarily reflect homogeneity in the HPA axis disturbances of such patients.