Does depressive illness in the elderly have a poor prognosis?

The few available longitudinal studies of depressive illness in the elderly indicate a poor prognosis. Various risk factors are discussed. Both severe and chronic physical illness, and severity of the depressive disorder are the two most important prognostic factors. The possibility of interactional effects between these risk factors should be studied. Most studies to date have been of severely depressed patients and this may give an unduly pessimistic picture. A case is made for the desirability of well-designed prognostic longitudinal studies with subjects being drawn from a wide spectrum of severity of illness.