Risk of suicide attempt and suicide death in patients treated for bipolar disorder

Objectives: To evaluate demographic and clinical predictors of suicide attempt and suicide death in a population-based sample of people treated for bipolar disorder (BD). Methods: Computerized records were used to identify 32,360 individuals treated for BD at two large prepaid health plans. Suicide attempts were identified using computerized records of outpatient visit diagnoses and hospital discharge diagnoses. Suicide deaths were identified using state death certificate data. Results: Overall event rates were 1.06 per 1,000 person-years for suicide death, 5.6 per 1,000 person-years for suicide attempt leading to hospitalization, and 13.9 per 1,000 person-years for suicide attempt not leading to hospitalization. Men had a significantly lower rate of suicide attempt [hazard ratio (HR) 0.68, 95% confidence interval (CI) 0.56-0.83] but a higher rate of suicide death (HR 2.70, 95% CI 1.69-4.31). Suicide attempts were significantly more frequent among younger patients, but suicide deaths did not vary significantly by age. Substance use comorbidity was significantly related to risk of suicide attempt (HR 2.53, 95% CI 2.07-3.09) but not to risk of suicide death (HR 1.02, 95% CI 0.54-1.93). Comorbid anxiety disorder was associated with significantly higher risk of both suicide attempt (HR 1.40, 95% CI 1.14-1.72) and suicide death (HR 1.81, 95% CI 1.09-2.99). Conclusions: Among people treated for BD, risk of suicide death is significantly related to male sex and comorbid anxiety disorder. The predictors of suicide death differ markedly from predictors of suicide attempt.