Risk of Stroke in Patients With Schizophrenia, Bipolar Disorder, and Major Depressive Disorder: A Cohort Study of 183,504 Subjects.

BACKGROUND: Major psychiatric disorder, including schizophrenia, bipolar disorder, and major depressive disorder, has been individually associated with increased risk of stroke. However, few studies have directly compared the stroke risk across these diagnostic groups within a unified cohort framework while accounting for stroke subtypes and relevant confounders. METHODS: Using Taiwan's National Health Insurance Research Database, we identified 30,945 patients with schizophrenia, 30,360 with bipolar disorder, 30,447 with major depressive disorder, and 91,752 age-matched controls without psychiatric illness between 2001 and 2009. Participants were followed until death or the end of 2011. Cox regression models were used to estimate the hazard ratio (HR) for ischemic and hemorrhagic stroke, adjusting for potential confounding factors. Sensitivity analyses were conducted by excluding stroke events occurring within the first 1 or 3 years of psychiatric diagnosis. RESULTS: All three psychiatric groups exhibited significantly higher risks of ischemic and hemorrhagic stroke compared with controls. Stroke risk remained consistently elevated across age and sex strata for all psychiatric groups. Greater cumulative exposure to antidepressants was associated with reduced stroke risk across all three disorders; antipsychotics showed protective associations in schizophrenia and bipolar disorder, non-lithium mood stabilizers were protective only in bipolar disorder, and lithium showed no significant association with stroke risk. CONCLUSION: Schizophrenia, bipolar disorder, and major depressive disorder are independently associated with increased stroke risk. These findings highlight the need for integrated vascular risk monitoring in psychiatric care.