Causal relationship between mental illness and venous thromboembolism: a Mendelian randomization study.

Previous findings on the relationship between mental disorders and venous thromboembolism (VTE) are controversial, and the precise causal relationship remains unclear. This study investigated the association between mental disorders and VTE based on the analysis of pooled data from large-scale genome-wide association studies (GWAS). Mendelian randomization (MR) was used to assess the causal relationships between bipolar disorder, schizophrenia, and VTE, with inverse variance weighting (IVW) as the primary statistical method. Furthermore, the F-statistic checks instrument stability; Cochran’s Q assesses heterogeneity; and the weighted median, MR-Egger, and leave-one-out methods were applied to evaluate sensitivity and pleiotropy. We found that genetically predicted bipolar disorder was significantly associated with VTE (IVW: odds ratio [OR] = 0.833, 95% confidence interval [CI] 0.704–0.985, P = 0.032). In addition, MR using the IVW method revealed a significant association between schizophrenia and VTE (IVW: OR = 0.917, 95% CI 0.869–0.9685, P = 0.002). Complementary MR methods and sensitivity analyses further confirmed the reliability of the MR findings. Overall, the results of this study demonstrated the causal relationship among bipolar disorder, schizophrenia, and VTE. Further research is essential to validate these findings and elucidate their causal mechanisms.