Background and purpose: Although the relationship between depression and stroke risk has been investigated, findings in previous reports were conflicting. The aim of this study was to prospectively examine the effect of major depressive episodes (MDE) on stroke incidence and further assess the potential dose-response relationship between number of depression symptoms and subsequent stroke risk in Chinese population.
Methods: A total of 199 294 men and 288 083 women aged 30 to 79 years without a history of stroke, heart disease, and cancer in the China Kadoorie Biobank cohort were followed from 2004 to 2013. A World Health Organization Composite International Diagnostic Interview-Short Form was used to access MDE according to Diagnostic and Statistical Manual of Mental Disorders-IV criteria. Stroke events were ascertained through death certificates, medical records, and health insurance data.
Results: Past year MDE was marginally associated with a 15% increased risk of stroke (adjusted hazard ratio, 1.15; 95% confidence interval, 0.99-1.33) in the fully adjusted model, and the association was steeper and statistically significant in individuals aged <50 years, smokers, drinkers, those with higher education degree, body mass index <24.0 kg/m(2), and no history of diabetes mellitus. Moreover, there was a positive dose-response relationship between the number of depression symptoms and increased stroke risk (Ptrend=0.011). In addition, smoking status significantly interacted with MDE on stroke onset (P for multiplicative interaction=0.025).
Conclusions: Findings from this large prospective study suggest that the presence of MDE is a risk factor for stroke, especially in smokers.
Keywords: depression; prospective study; stroke.
© 2016 American Heart Association, Inc.