The aim of the present study was to investigate various risk factors of suicidal behaviors, including the mixed features specifier, in Korean patients with bipolar disorder.

We retrospectively reviewed medical charts from 2005 to 2014. A total of 334 patients diagnosed with bipolar disorder using the DSM-IV TR were enrolled. Subjects were categorized into two groups according to their history of suicidal behavior and the demographic and clinical characteristics of the groups were compared, including the mixed features specifier. We re-evaluated the index episode using DSM-5 criteria and classified subjects into an index episode with mixed features group and an index episode without mixed features group. Logistic regression was performed to evaluate significant risk factors associated with suicidal behavior.

Suicidal behavior had an independent relationship with mixed features at the index episode using DSM-5 criteria (OR = 3.39; 95% CI: 1.57–7.34) and number of previous depressive episodes (OR = 1.62; 95% CI: 1.34–1.95) in Korean bipolar patients. The mixed feature specifier was the strongest risk factor for suicidal behavior in the present study. Limitations: this was a retrospective study and structured psychiatric interviews were not conducted.

This study may help clinicians understand potential risk factors and manage bipolar disorders with suicidal behaviors. Clinicians should carefully monitor patients with bipolar disorder who exhibit numerous depressive episodes or mixed features for suicidal behavior.

The authors have not supplied their declaration of competing interest.