Objective To explore the impact of depressive symptoms on quality of life in patients with bipolar disorder and the mediating psychological factors involved.

Methods Using convenience sampling, 235 patients with bipolar disorder who visited outpatient clinics and inpatient wards of the Departments of Psychiatry at the Third Affiliated Hospital of Sun Yat-sen University, the Affiliated Brain Hospital of Guangzhou Medical University, and Xiamen Xian Yue Hospital from April 2019 to September 2025 were enrolled, along with 68 healthy individuals from the Zhongshan 2nd Road Community and the Guanjun Community in Guangzhou. Participants were assessed using a general information questionnaire, the Hamilton Depression Rating Scale-17 (HDRS-17), the Young Mania Rating Scale (YMRS), neurocognitive function tests, the Resilience Questionnaire for Bipolar Disorder (RBD), the Rosenberg Self-Esteem Scale (RSES), the Functioning Assessment Short Test (FAST) and the 12-item Short-Form Health Survey (SF-12). Pearson correlation analysis and multiple linear regression analysis were performed, and a mediation effect model was constructed and tested.

Results Both the SF-12 physical component summary (PCS-12) score (r = −0.298, P ＜ 0.001) and the mental component summary (MCS-12) score (r = −0.422, P ＜ 0.001) of quality of life were negatively correlated with depressive symptoms score. The MCS-12 score of quality of life was also negatively correlated with self-esteem score (r = −0.321, P ＜ 0.001) and positively correlated with resilience scores (r = 0.158, P = 0.026). Further regression analyses showed that more severe depressive symptoms (t = −3.571, P ＜ 0.001), older age (t = −3.088, P = 0.002), and greater impairment in the cognitive functioning dimension of psychosocial functioning (t = −2.696, P = 0.008) were associated with poorer quality of life in the physical component. More severe depressive symptoms (t = −3.992, P ＜ 0.001), higher self-esteem level (t = −3.439, P = 0.001), greater impairment in the interpersonal relationships dimension of psychosocial functioning (t = −2.830, P = 0.005), better quality of life in the physical component (t = −2.579, P = 0.011), and higher educational level (t = −2.268, P = 0.024) were associated with poorer quality of life in the mental component. The mediating effect model indicated that depressive symptoms could directly predict the MCS-12 (β = −0.317) and could also influence it through three pathways: self-esteem (β = −0.081), resilience (β = −0.022), and a chain mediation pathway involving self-esteem and resilience (β = −0.028).

Conclusion  Depressive symptoms have a direct impact on the mental component of quality of life in patients with bipolar disorder and also exert indirect effects through the mediating role of self-esteem, the mediating role of resilience, and the chain mediating effects of self-esteem and resilience.