Mortality in patients with primary unipolar depression, secondary unipolar depression, and bipolar affective disorder: a comparison with general population mortality.

Mortality data are presented from a two to fourteen year follow-up of 705 primary unipolar depressives, 302 secondary unipolar depressives, and 586 patients with bipolar affective disorder (BAD) hospitalized at a tertiary care facility. Death ascertainment was made through a record-linkage process. Using sex- and age-standardized mortality ratios (SMRs), the mortality experience of the study population was compared with that of Iowa, the geographical area served by the admitting medical facility for this study group. Results show that risk for all-cause mortality was most pronounced during the first two years following hospital discharge, although secondary unipolar depressives continued to show a significant excess of deaths throughout the entire follow-up period. Deaths occurring from natural causes were significantly excessive only during the initial portion of the follow-up. Deaths from unnatural causes were significantly excessive throughout follow-up except for patients with bipolar affective disorder.