Static and Dynamic Effects of Stroke Onset on Depressive Symptoms in Middle-Aged and Older Adults: Evidence Across 21 Countries.

BACKGROUND: Stroke and depressive symptoms are significant public health concerns worldwide; however, their causal relationship remains unclear. Therefore, there is a need for comprehensive multicountry studies that examine both static and dynamic effects over time.

METHODS AND RESULTS: We conducted a pooled multicohort study across 21 countries using nationally representative longitudinal data sets. Our sample was restricted to individuals aged ≥50 years who were followed for at least 2 waves. First, the fixed-effects model in conjunction with propensity score matching was used to analyze the static effect of stroke onset on depressive symptoms. Next, by using an event study methodology, we delved into the dynamic relationship. Furthermore, meta-analyses and multilevel model were conducted to assess heterogeneity and explore the moderating role of national-level indicators. Our study revealed a statistically significant and robust causal linkage between stroke onset and depressive symptoms. Further analysis highlighted both the anticipatory effects of stroke occurrence and the sustained, substantive impact on depressive symptoms over more than a decade. Meta-regression analyses indicated that countries with higher mortality from noncommunicable diseases exhibited attenuated effect sizes. Furthermore, we observed a modest moderating effect of mortality from noncommunicable diseases and life expectancy.

CONCLUSIONS: This research underscores the complex relationship between stroke and depressive symptoms, highlighting the need to further identify underlying mechanisms.