Dexamethasone suppression test and response to antidepressant therapy in psychogeriatric patients.

Senile dementia patients show a high incidence of abnormal Dexamethasone Suppression Test (DST) which has been suggested to reflect the presence of atypical or subclinical depression; this study was designed to test this hypothesis. Thirty-six patients, diagnosed as suffering from dementia and/or depression on the DSM-III criteria, participated in the study. They were divided into three groups. dementia (12), depression (12) and dementia with depression (12). The results indicated that although patients with depression alone responded well to antidepressant therapy, no improvement occurred in patients with dementia. Demented patients who had clinical depression also showed a poor response. The response to treatment was unrelated to the DST status of the patients. It is concluded that abnormal DST in dementia patients is not indicative of a masked affective state, and antidepressants have no place in the management of dementia patients who have a positive DST but no overt affective symptoms.