Response to dexamethasone in psychotic depression.

The utility of the dexamethasone suppression test (DST) in the diagnosis of psychotic depression was examined by comparing the responses of 11 psychotic and 18 nonpsychotic depressed inpatients. Nine of 11 psychotic patients (81.8%) and 10 of 18 nonpsychotic patients (55.6%) showed nonsuppression (nonsignificant). Using the 0800h cortisol level alone, we found that significantly more psychotic patients (7 of 11; 63.6%) than nonpsychotic patients (3 of 18; 16.7%) showed nonsuppression. Nonsuppression at 0800h postdexamethasone may be a useful biologic marker for patients with psychotic depression. Implications of these data for the nosologic status of psychotic depression are discussed.