Interplay between coronary heart disease and depression: associations with mental and physical health

BACKGROUND: While the associations between coronary heart disease (CHD) and depression are well-documented, their synergistic interplay requires quantification in large, representative populations. Operating within a cross-sectional framework, this study’s objective was to investigate the associations of CHD and depression with current health status and to explore their interaction using a nationally representative U.S. sample. METHODS: This study utilized data from 172,741 participants in the 2022 Behavioral Risk Factor Surveillance System (BRFSS). CHD and depression were based on self-reported history. Outcomes were frequent physical and mental distress (≥ 14 unhealthy days in the past 30 days). We used multivariable logistic regression with inverse probability of treatment weighting (IPTW) to adjust for confounding and estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs). An exploratory analysis assessed the extent to which the association between CHD and health status was statistically explained by depression, and additive interaction was also examined. RESULTS: After IPTW adjustment, CHD was significantly associated with a higher likelihood of both frequent physical distress (aOR = 1.47, 95% CI: 1.35–1.60) and frequent mental distress (aOR = 2.59, 95% CI: 2.44–2.75). Depression statistically explained 2.19% of the association between CHD and poor physical health and 21.69% of the association with poor mental health. A significant positive additive interaction was found between CHD and depression. The synergy index indicated that their combined association with poor physical health was 1.26 times greater, and with poor mental health was 1.40 times greater, than the sum of their individual associations. CONCLUSION: In a large U.S. adult sample, CHD and depression are independently and synergistically associated with poorer physical and mental health. These findings underscore the importance of integrated care models that address both conditions to improve patient well-being.