Saunders, Erika F.H.

Abstract Background The Global Bipolar Cohort (GBC) was established to identify existing bipolar disorder (BD) cohorts worldwide and foster collaborations focused on descriptive and analytic outcomes relevant to BD. A distributed analytic framework has been implemented to engage multiple sites without the need for central data pooling. This report describes the GBC endeavor and global functional impairment patterns. Cross-cohort comparisons of functional correlates are limited by heterogeneous measures and data-sharing constraints. Large, culturally diverse comparisons are needed to distinguish broadly reproducible correlates from cohort-specific effects. Participating sites completed a 28-item descriptive survey covering diagnostic methods, cognition, genetics, treatment, functioning, and follow-up strategies. We implemented a harmonized local logistic regression model of dichotomized functional outcome and shared summary statistics only. Results We identified 69 cohorts across five continents. Thirty-seven cohorts contributed functional outcome analyses from 17,130 participants. Outcome measures included clinician-rated disability scales and social indicators such as employment and marital status. The proportion classified with poor functioning ranged from 16% to 77% (mean 50%). In 32 of 37 cohorts, the overall regression model significantly explained variance in functioning. Current depressive symptoms were the most robust and reproducible correlate of poor functional outcome: they were assessed in 29 cohorts, significant in 22 (75.8%), ranked among the top three correlates in 22, and were the top-ranked correlates in 19. Associations between depressive burden and poor functioning were observed across clinician-rated disability scales and work or social indicators, and across geographically diverse cohorts. Comorbid substance use disorder and medication-related variables were associated with poorer functioning in subsets of cohorts, whereas sex, ancestry, bipolar subtype, psychosis history, and premorbid IQ showed weak or inconsistent associations. Cognitive measures, available in a minority of regression models, showed modest and non-uniform effects. Conclusions Across heterogeneous international cohorts, current depressive symptom burden emerged as the most consistent correlate of poor functioning in bipolar disorder. These findings replicate earlier multisite work at a larger scale, show that protocol-based distributed analyses can identify reproducible clinical signals without sharing individual-level data, and support prioritizing detection and treatment of depressive symptoms when aiming to improve real-world functioning. Future work should expand longitudinal harmonization and representation of under-studied populations.

Background: Bipolar disorder (BD) is associated with a higher prevalence of chronic kidney disease (CKD) and increased mortality, yet individuals with both BD and CKD are less likely to receive kidney replacement therapy (KRT). Sodium-glucose cotransporter-2 inhibitors (SGLT2is) provide renal protection in diabetes, but their long-term effects in this high-risk population remain unknown. Objectives: To evaluate whether SGLT2i use reduces the risk of KRT and all-cause mortality in adults with BD and mild-to-moderate CKD (stage ⩽ 3). Design: Observational cohort study with propensity score matching (PSM). Method: In this study using TriNetX (2009–2024) real-world database, 89,369 adults with BD and mild-to-moderate CKD were classified as SGLT2i users ( n = 12,736) or nonusers ( n = 76,633). Primary outcomes were progression to KRT and all-cause mortality over 5 years. Adjusted hazard ratios (aHRs) were estimated using Cox proportional hazards models, and 1:1 PSM reduced confounding. Subgroup analyses examined sex, race/ethnicity, diabetes status, CKD stage, and mood stabilizer use. Results: SGLT2i use was associated with lower risk of KRT (aHR 0.47 (95% CI, 0.42–0.53)) and all-cause mortality (aHR 0.69 (95% CI, 0.65–0.73); both p < 0.001). Protective effects were consistent across subgroups, including individuals receiving lithium, lamotrigine, valproate, or antipsychotics. After PSM (10,967 matched pairs), 5-year KRT-free survival was 94.61% versus 90.99%, and overall survival was 78.67% versus 67.53% (both p < 0.001). Given the observational design, the possibility of residual or unmeasured confounding canot be excluded. Conclusion: SGLT2i therapy in individuals with BD and mild-to-moderate CKD is associated with substantially lower risks of KRT and all-cause mortality. Prospective trials are needed to confirm these findings.