The 5-year prognosis of 42 elderly patients with major depression (mean age 73.2 +/- 6.3 years for men and 73.0 +/- 7.3 years for women) is described. Furthermore, the clinical outcome of elderly patients with major depression is compared to that of 199 elderly patients with dysthymic disorder (mean age 69.9 +/- 7.2 years for men and 71.3 +/- 7.7 years for women) described in a previous article. Twelve percent of patients with major depression recovered, 26% still had depression after 5 years, 12% had possible dementia, 45% had died, and 5% could not be contacted. The outcome did not significantly differ between the sexes or the two age groups (65-74 and 75+). A poor clinical outcome of patients with major depression was related to a greater number of diagnosed diseases, strong feelings of restlessness, and higher sexual interest at the beginning of the follow-up. A poor prognosis was also found for the patients whose functional abilities and hobby activities declined during the follow-up. A poor prognosis tended to be related to absence of hypertension, frequent trembling of hands, low activity in listening to music, and high activity in watching TV at the onset, and to absence of malignant disease and occurrence of a high number of negative and positive life events during the follow-up period. Thirty-six percent of dysthymic patients recovered, 26% still had depression after 5 years, 9% had possible dementia, 25% had died and 4% could not be contacted. The outcome of dysthymic patients did not significantly differ between the sexes or the two age groups (65-74 and 75+). The clinical outcome of dysthymic patients tended to be more favorable than that of patients with major depression. The factors related to a poor outcome differed between patients with major depression and dysthymic patients.