Causal Relationship Between Hypertension and Schizophrenia

Hypertension is a significant risk factor for cardiovascular diseases, kidney disease, and psychiatric illnesses, and a major global issue. Schizophrenia is a chronic psychiatric disorder with inconsistent behavioral and cognitive abnormalities, profoundly impacting individuals and society. There is a close relationship between hypertension and schizophrenia, but the exact causal link remains unclear. We employed bidirectional Mendelian randomization (MR) analysis to evaluate the causal association of hypertension and schizophrenia. These instruments were derived from genome-wide association study (GWAS) datasets. The inverse-variance weighted (IVW) method was employed, complemented by sensitivity analyses to ensure robustness of the findings. In the discovery group, no significant causal associations were found between genetically predicted hypertension on the risk of schizophrenia (OR: 0.836, 95% CI: 0.491-1.424, P > 0.05). Similarly, in the validation group and meta-analysis, no significant causal associations were found (OR: 1.050, 95% CI: 0.796-1.385, P > 0.05; OR: 1.000, 95% CI: 0.783-1.279, P > 0.05). For the reverse analysis, genetically predicted schizophrenia was not associated with an increased risk of hypertension (OR: 0.999, 95% CI: 0.992-1.007, P > 0.05). Sensitivity analyses confirmed the robustness of these findings. In conclusion, this study indicates no causal link between hypertension and schizophrenia.