Different characteristics associated with suicide attempts among bipolar I versus bipolar II disorder patients

Abstract

Background: Suicide attempts are common in patients with bipolar disorder (BD), and consistently associated with female gender and certain unfavorable BD illness characteristics. Findings vary, however, regarding effects of BD illness subtype and yet other illness characteristics upon prior suicide attempt rates. We explored the effects of demographics and BD illness characteristics upon prior suicide attempt rates in patients stratified by BD illness subtype (i.e., with bipolar I disorder (BDI) versus bipolar II disorder (BDII)).

Methods: Outpatients referred to the Stanford BD Clinic during 2000-2011 were assessed with the Systematic Treatment Enhancement Program for BD Affective Disorders Evaluation. Rates of prior suicide attempt were compared in patients with and without diverse demographic and BD illness characteristics stratified by BD subtype.

Results: Among 494 BD outpatients (mean ± SD age 35.6 ± 13.1 years; 58.3% female; 48.6% BDI, 51.4% BDII), overall prior suicide attempt rates in were similar in BDI versus BDII patients, but approximately twice as high in BDI (but not BDII) patients with compared to without lifetime eating disorder, and in BDII (but not BDI) patients with compared to without childhood BD onset. In contrast, current threshold-level suicidal ideation and lifetime alcohol use disorder robustly but less asymmetrically increased prior suicide attempt risk across BD subtypes.

Limitations: American tertiary bipolar disorder clinic referral sample, cross-sectional design.

Conclusions: Further studies are needed to assess the extent to which varying clinical characteristics of samples of patients with BDI and BDII could yield varying prior suicide attempt rates in patients with BDI versus BDII.

Keywords: Bipolar I disorder (BDI); Bipolar II disorder (BDII); Childhood onset; Comorbidity; Depression; Suicide attempts.