Effects of chronic medical illness and dementia on the dexamethasone suppression test.

The dexamethasone suppression test (DST) was performed on 26 elderly male outpatients in a geriatric medical clinic. Patients with depression were excluded. All patients had two or more medical diagnoses. Fourteen patients also met DSM-III criteria for dementia. No patient had an abnormal DST result. The authors suggest that neither chronic medical illness nor dementia causes false-positive DST results in this patient population in an outpatient setting, and discuss the findings in relation to previous reports.