In a prospective study, 186 unipolar depressives and 220 cases of bipolar disorder meeting DSM-III criteria for major depression or mania were followed up. Subjects were classified according to polarity and the presence or absence of schizophrenic symptoms, into four diagnostic subgroups: unipolar depression, bipolar disorder, unipolar schizoaffective disorder and bipolar schizoaffective disorder. At the last follow-up in 1985, 53% of the patients had deceased. Eleven percent of the sample (17% of all deaths) had committed suicide. The risk of suicide was associated with clinical severity and onset prior to the age of 60. However, there was no difference in suicide rates according to sex or diagnostic subgroup. Late onset of affective illness was associated with chronicity, which occurred in 10 to 19% of cases. Recovery was more frequent among unipolar than among bipolar patients. The 5-year remission rates (i.e. 26% in unipolars, 16% in bipolars) were independent of the number of episodes.