Quality of life in patients with euthymic bipolar disorder: a systematic review and meta-analysis of comparative studies

Introduction: Bipolar disorder (BD) is a chronic psychiatric condition associated with significant impairments in quality of life (QoL). Although relevant studies have been conducted, findings on QoL among euthymic BD patients have been inconsistent. This systematic review and meta-analysis aimed to quantify QoL impairments across different domains in euthymic BD patients compared to healthy controls and examine potential moderators. Methods: A comprehensive search of major international (PubMed, PsycINFO, EMBASE and Web of Science) and Chinese databases (CNKI and Wanfang) was conducted. Comparative studies assessing QoL in euthymic BD patients and healthy controls using validated instruments were included. Standardized mean differences (SMDs) were calculated using a random-effects model. Subgroup and meta-regression analyses were performed to investigate potential moderators. Results: Twenty-seven studies of 2055 euthymic BD patients and 3576 healthy controls were included. Euthymic BD patients exhibited significant QoL impairments across all specific QoL domains compared to healthy controls, with the largest effect sizes observed for the physical domain [SMD =-1.13, 95 % confidence interval (95 %CI):-1.66 to −0.61, p < 0.001] and social relationship domain (SMD = -1.16, 95 %CI:-1.71 to −0.60, p < 0.001) of the World Health Organization Quality of Life Questionnaire (WHOQOL). Meta-regression analyses found that larger sample sizes were associated with smaller group differences in WHOQOL psychological and social QoL domains. Conclusions: QoL impairments persist in euthymic BD patients compared to non-patient controls across all domains. Findings highlight the need for comprehensive interventions targeting residual symptoms, comorbidities, and psychosocial influences to improve QoL outcomes of this patient population.