The individual and combined associations of depression and socioeconomic status with risk of major cardiovascular events: a prospective cohort study

Objective We aimed to investigate the individual and combined associations of depression and low socioeconomic status (SES) with risk of major cardiovascular events (MCVE), defined as first-ever fatal or non-fatal stroke or myocardial infarction, in a large prospective cohort study. Methods We used data from 466,238 UK Biobank participants, aged 40 – 69 years without cardiovascular disease, bipolar disorder or schizophrenia at baseline. We performed Cox proportional hazard models to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) of the individual and combined associations of depression and each of educational attainment, area-based deprivation and income with risk of MCVE. We assessed effect modification and explored interaction on the additive and multiplicative scale. Results Depression, low education, high area-based deprivation and low income were individually associated with increased risks of MCVE (adjusted HR, 95% CI: 1.28, 1.19 – 1.38; 1.20, 1.14 – 1.27; 1.17, 1.11 – 1.23; and 1.22, 1.16 – 1.29, respectively). Depression was associated with increased risks of MCVE among individuals with high and low SES. Individuals with depression and each of low education, high area-based deprivation and low income were at particularly high risk of MCVE (HR, 95% CI: 1.50, 1.38 – 1.63; 1.63, 1.46 – 1.82; 1.31, 1.23 – 1.40, respectively). There was interaction between depression and area-based deprivation on multiplicative and additive scales but no interaction with education or income. Conclusion Depression was associated with increased risks of MCVE among individuals with high and low SES, with particularly high risks among those living in areas of high deprivation.