Dexamethasone suppression test and serum prolactin in dementia disorders.

The dexamethasone suppression test (DST) was performed on 21 patients with dementia of the Alzheimer type (DAT), 11 patients with multi-infarct dementia (MI) and 14 healthy controls. Twelve of the DAT patients and eight of the MI patients showed abnormal lack of suppression, compared with just one member of the control group. Abnormal DST was related to dementia as such and not to age or depression, or to levels of CSF monoamine metabolites. Basal serum prolactin concentrations were not increased.