Search

Background: Both stroke and psychosis are independently associated with high levels of disability. However, psychosis in the context of stroke has received remarkably little interest from clinicians and researchers. To date there are currently no population studies on their joint prevalence and association. Methods: We estimated the prevalence of i) probable psychosis in stroke and, ii) stroke in probable psychosis using four nationally representative cross-sectional psychiatric epidemiological studies: two from high-income countries (United Kingdom and United States) and two from middle-income countries (Chile and Colombia) and, subsequently, a combined dataset from all four countries. We also tested the statistical association between stroke and psychosis using single and multi-level regression models to estimate the unadjusted association between stroke and psychosis, and the association adjusted for potential demographic confounders. Results: The prevalence of probable psychosis in stroke ranged from 1.05% [95% CIs 0.03 - 5.73] in Chile, to 13.92% [95% CIs 7.16 - 23.55] in Colombia, with the prevalence from the combined countries dataset estimated at 3.81% [95% CIs 2.34 - 5.82]. Stroke in probable psychosis ranged from 2.18% [95% CIs 1.09 - 3.86] in Colombia, to 16.67% [95% CIs 6.37 - 32.81] in the US, with the combined countries prevalence estimated at 3.15% [95% CIs 1.94 - 4.83]. Estimates for the adjusted association between stroke and probable psychosis ranged from an OR = 1.11 [95% CIs 0.15 - 8.26] in the UK to an OR = 6.22 in the US [95% CIs 2.52 - 15.35] with the adjusted association from the combined dataset estimated at OR = 3.32 [95% CIs 2.05 - 5.38]. Larger prevalences and associations were associated with larger confidence intervals and we suggest the smaller estimates are likely to be more accurate. We also examined the association between stroke and paranoia, hallucinated voices, and thought passivity delusion, and although we found significant variation in the reliability and strength of association across countries, all three psychotic symptoms were associated with stroke in the unadjusted and adjusted analyses in the combined countries dataset. Conclusions: There are high rates of association between psychosis and stroke, meaning there is likely a high clinical need group who are under-researched and may be poorly served by existing services. Notably, stroke is a known risk factor for psychosis, and psychosis and antipsychotic treatment for psychosis are known risk factors for stroke, meaning causality is likely to be bidirectional and treatment pathways should be integrated across traditional service boundaries.