HPA axis abnormalities in depressed patients with normal response to the DST.

In order to identify depressed patients with hypothalamic-pituitary-adrenal (HPA) axis abnormalities who have a normal response to the dexamethasone suppression test (DST), the authors administered a series of neuroendocrine tests including insulin-induced hypoglycemia, arginine vasopressin challenge, and a DST. Using standard sensitivity measures, as well as logistic regression, they concluded that many patients with HPA abnormalities are not identified by the DST. These findings suggest that other neuroendocrine tests, which are sensitive to HPA axis abnormalities, may be helpful in subtyping depression on the basis of HPA axis functioning.