Do depression and anxiety mediate the link between educational attainment and CHD?

Objective: Depression and anxiety are frequently hypothesized yet rarely examined pathways linking low socioeconomic status (SES) to coronary heart disease (CHD). This study evaluates depression and anxiety as mediators of the association between educational attainment and incident CHD. Methods: Subjects (n = 6265, age 25-74) were participants in NHANES 1 and follow-up studies, a longitudinal, nationally representative study of the US population. Measures of educational attainment and depressive and anxious symptoms (General Well-Being Schedule) were derived from the baseline interview and incident CHD from hospital records and death certificates. Analyses included logistic regression and Cox proportional hazards models. Results: In fully adjusted models, less than high school (relative risk [RR] = 1.46; 95% confidence interval [CI], 1.15-1.86) and some college (RR = 1.40; 95% CI, 1.05-1.88) education were associated with increased CHD risk relative to a college education. High depressive (RR = 1.31; 95% CI, 1.06-1.61) or anxious (RR = 1.35; 95% CI, 1.13-1.62) symptoms were associated with significantly increased CHD risk relative to low symptoms. Low educational levels were associated with increased risk for high depressive (OR = 3.43; 95% CI, 2.34-5.03) and anxious (OR = 1.71; 95% CI, 1.32-2.22) symptoms. However, depressive and anxious symptoms accounted for little of the association between education and CHD. Conclusion: Education and depressive and anxious symptoms are associated with each other and risk of incident CHD. Although depressive and anxious symptoms are highest among those with lowest levels of education, they do not appear to mediate the relation between educational attainment and incident CHD. Findings suggest the importance of interventions to reduce socioeconomic disadvantage and negative affect in preventing CHD.