Psychiatria Fennica (Nov 2018)
PSYCHOPHARMACOLOGICAL TREATMENT, MORTALITY AND SUICIDE IN BIPOLAR DISORDER IN A FINNISH NATIONWIDE COHORT OF 18,018 PATIENTS
Abstract
Bipolar disease has been associated with high overall mortality and a marked decrease in life expectancy. Suicide is one of the most common causes of death in bipolar disorder. In recent years, use of antidepressants and anticonvulsants has increased at the expense of lithium in the treatment of this disorder. Not much “real-world” data from large inclusive cohorts is available to determine whether this switch in treatment preference could affect risk of suicide in bipolar patients. We aimed to study the risks associated with the use of pharmacological treatment on suicide and overall mortality in a nationwide cohort of Finnish patients with bipolar disorder (n=18018). We studied the risk of overall and suicide mortality between 1996–2012 among all patients who had been hospitalized due to bipolar disorder in Finland (n=18018; mean follow-up time 7.2 years) using prospectively gathered nationwide databases for hospitalization and dispensed medication. The primary analysis was a Cox proportional hazards model. Analyses were adjusted for the effects of time since diagnosis, order of treatments, current use of other treatments, polypharmacy within medication group, number of hospitalizations within 2 years (indicator of inherent risk of relapse), age at index date, gender and calendar year of index date. Results are reported as hazard ratios (HRs) with 95% confidence intervals (95% CI). In comparison between use and no use of medication groups reaching nominal statistical significance, use of mood stabilizers was associated with a 51% reduction in overall mortality (HR 0.49, 95% CI 0.44-0.54, p<0.001) and antidepressants with a 26% reduction in overall mortality (HR 0.74, 95% CI 0.67-0.81, p<0.0001). Use of mood stabilizers was associated with a 53% reduction in suicide mortality (HR 0.47, 95% CI 0.38-0.58, p<0.0001), whereas use of sedatives was associated with a significantly increased risk for suicide (HR 1.52, 95% CI 1.22-1.90, p=0.0002). In conclusion, mood stabilizers should be considered as treatment of choice for patients with bipolar disorder who are at high risk for suicide. Use of sedatives should be avoided to the fullest extent possible.
