The dexamethasone suppression test: interaction of diagnosis, sex, and age in psychiatric inpatients.

A group of 277 semiconsecutive psychiatric inpatients manifesting a depressive affect underwent an overnight 1 mg dexamethasone suppression test (DST) and a semistructured diagnostic interview according to DSM-III criteria. For major depressive syndromes (major depression with and without psychosis, bipolar depressed) the sensitivity of the DST was 63.9%, specificity 73.0%, and diagnostic confidence 72.3%. Additionally, a significant interaction between age and baseline cortisol values and nonsuppression rates was found in depressed males but not in nondepressed males nor in depressed and nondepressed females. The authors discuss the implications of these findings.