The dexamethasone suppression test in depressed and non-depressed geriatric medical inpatients.

The frequency of an abnormal response to the dexamethasone suppression test (DST) was examined in 38 geriatric patients hospitalized for medical illnesses and affected by depressive disorders diagnosed according to the DSM III, and in 18 medical patients (used as controls) hospitalized in the same ward. Only 11% of the controls and 11% of those affected by dysthymic disorder had an abnormal DST vs 73% of the patients with major depressive disorder (MDD). The sensitivity of the DST for MDD, in this particular setting, was found to be about 73% and the specificity 89%. The importance of this clinical adjunct in diagnosing the severe depressive disorders is discussed.