Journal of International Psychiatry

Objective To explore the mixed episodes of bipolar disorder and analyze its influencing factors. Methods During February 2013 to June 2014, 520 patients with bipolar disorder were selected from 7 hospitals in China by continuous sampling method. The demographic data, medical history information, disease characteristics, treatment and other clinical data were collected. We investigated the number of mixed episodes of bipolar disorder and analyzed the influencing factors by Poisson regression model. Results Among 520 patients with bipolar disorder, 75 cases (14.42%) were mixed episodes, including 72 cases type I and 3 cases type II. Poisson regression model analysis showed that the risk factors of mixed episodes included: Type I patients had more episodes than type II (IRR =0.068, p < 0.001). Patients with family history of mental illness had more mixed episodes (IRR =1.435, p=0.037). Patients with non-manic polarity at first episode had more mixed episodes than manic patients (IRR =9.988, p < 0.001). Non-depressed patients at first episode had more episodes than depressed patients (IRR =6.241, p < 0.001). Patients taking mood stabilizers had more mixed episodes (IRR =0.561, p=0.001). Conclusion Mixed episodes of bipolar disorder are closely related to the type of bipolar disorder, family history of mental illness, polarity of first episode and use of mood stabilizers.

Bipolar disorder; Mixed episodes; Influencing factor