The authors examined the frequency and severity of depressive symptoms in elderly patients with presumed primary degenerative dementia and identified the signs and symptoms that provide a reliable basis for diagnosing depression. Forty-four patients and 42 control subjects were interviewed and rated on the Hamilton Rating Scale for Depression and the Sandoz Clinical Assessment-Geriatric Scale. Nine of the patients demonstrated symptoms suggestive of mild, four of moderate, and five of severe depression. Patients had significantly higher scores than control subjects on items that assess intrapsychic rather than vegetative symptoms of depression. These findings underline the importance of maintaining a high index of suspicion for concomitant depressive symptoms in patients with primary degenerative dementia.