Abstract / Summary
Abstract Background Individuals with bipolar disorder (BD) exhibit lower psychological resilience and quality of life (QoL) than healthy individuals, but whether these outcomes differ between bipolar I disorder (BD-I) and bipolar II disorder (BD-II) remains unclear. This study compared psychological resilience and QoL among euthymic individuals with BD-I and BD-II and healthy controls. It also examined the associations between resilience and QoL. Methods The study included 51 euthymic patients with BD (BD-I n = 27; BD-II n = 24) and 43 healthy controls comparable in age, sex, and education. Psychological resilience was assessed using the Resilience Scale for Adults (RSA), QoL using the World Health Organization Quality of Life-BREF (WHOQOL-BREF), residual depressive symptoms using the Hamilton Depression Rating Scale (HAM-D), and perceived stress using the Perceived Stress Scale (PSS). Group comparisons, multiple regression, and hierarchical regression were performed. Benjamini–Hochberg corrections and influential-observation sensitivity analyses were used to assess the robustness of the findings. Results RSA scores were lower in the BD-II group than in the BD-I and healthy control groups ( p = 0.002). Participants with BD-II also had higher residual depressive symptoms and perceived stress scores, more lifetime depressive episodes, and poorer QoL across several domains. In the patient-level regression model, the association between BD-II diagnosis and lower resilience was attenuated and was no longer statistically significant after adjustment for number of depressive episodes and residual depressive symptoms. In the BD-II subgroup, resilience was positively associated with psychological QoL after adjustment for age, perceived stress, and residual depressive symptoms (β = 0.656, p < 0.001), and this association remained significant after correction for multiple testing. Conclusions Individuals with BD-II exhibited lower psychological resilience and poorer QoL in several domains compared with those with BD-I and healthy controls. The association between BD-II diagnosis and lower resilience was attenuated after adjustment for depressive episode burden and residual depressive symptoms; however, their relative contributions cannot be determined given the cross-sectional design and their clinical interrelationship. Psychological resilience remained associated with psychological QoL in BD-II after covariate adjustment. Psychological resilience may warrant further investigation as a potential therapeutic target in longitudinal and interventional studies.