Objectives There has been comparatively little research on the association between social capital and depressive symptoms in low- and middle-income countries. To address this deficit this study examined the association among middle-aged adults in rural Vietnam.Design A cross-sectional study.Setting Data came from the baseline survey of the Khánh Hòa Cardiovascular Study, which is an ongoing prospective cohort study aiming to elucidate the determinants of cardiovascular diseases.Participants A total of 3000 people aged 40–60 years old residing in rural communes in Khánh Hòa province, Vietnam.Exposure of interest Cognitive social capital (ie, low, middle and high) and structural social capital (in terms of social participation; yes or no) were assessed via a questionnaire.Primary outcome measure Depressive symptoms were assessed with the 11-item Center for Epidemiologic Studies Depression Scale.Results A robust Poisson regression model revealed that adults in the highest versus lowest cognitive social capital tertile had a 61% lower prevalence of depressive symptoms (prevalence ratio (PR)=0.39, 95% CI=0.31 to 0.49). Individuals with higher structural social capital were also significantly less likely to experience depressive symptoms (PR=0.74, 95% CI=0.61 to 0.90).Conclusion In a cohort of 3000 middle-aged rural residents in Vietnam, both cognitive and structural social capital assessed at the individual level were inversely associated with the prevalence of depressive symptoms.
