Excess mortality in bipolar and unipolar disorder in Sweden

Background: Selected groups of patients with bipolar and unipolar disorder have an increased mortality rate from suicide and natural causes of death. However, there has been no population-based study of mortality of patients followed up from the onset of the illness. Methods: All patients with a hospital diagnosis of bipolar (n = 15386) or u nipolar (n = 39182) disorder in Sweden from 1973 to 1995 were identified fr om the inpatient register and linked with the national cause-of-death regis ter to determine the date and cause of death. Overall and cause-specific st andardized mortality ratios (SMRs) and numbers of excess deaths were calcul ated by 5-year age classes and 5-year calendar periods. Results: The SMRs for suicide were 15.0 for males and 22.4 for females with bipolar disorder, and 20.9 and 27.0, respectively, for unipolar disorder. For all natural causes of death, SMRs were 1.9 for males and 2.1 for female s with bipolar disorder, and 1.5 and 1.6, respectively, for unipolar disord er. For bipolar disorder, most excess deaths were from natural causes, wher eas for unipolar disorder, most excess deaths were from unnatural causes. T he SMR for suicide was especially high for younger patients during the firs t years after the first diagnosis. Increasing SMR for suicide during the pe riod of study was found for female patients with unipolar disorder. Conclusions: This population-based study of patients treated in the hospita l documented increased SMRs for suicide in patients with bipolar and unipol ar disorder. The SMR for all natural causes of death was also increased, ca using about half the excess deaths.