Effect of comorbid chronic diseases on prevalence and odds of depression in adults with diabetes

Objective: The objective of this study was to determine the effect of coexisting chronic conditions on prevalence and odds of depression in individuals with diabetes. Methods: Data on 1794 adults with diabetes from the 1999 National Health Interview Survey were analyzed. Six chronic conditions were identified: hypertension, coronary artery disease, chronic arthritis, stroke, chronic obstructive pulmonary disease, and end-stage renal disease. Chronic conditions were counted and categorized into 4 groups: diabetes alone, diabetes + 1 condition, diabetes + 2 conditions, and diabetes + 3 or more conditions. Prevalence of depression was calculated by number of chronic conditions and for each condition. Adjusted odds of depression were calculated by number of chronic conditions and for each chronic condition while simultaneously controlling for covariates and for each chronic condition using multiple logistic regression. STATA was used for statistical analyses. Results: Using diabetes alone as reference, adjusted odds of major depression by number of conditions were: diabetes + 1 (1.31; 95% confidence interval [CI], 0.67-2.55), diabetes + 2 (2.09; 95% CI, 1.06-4.12), and diabetes + 3 or more (4.09; 95% CI, 2.04-8.17). Adjusted odds of major depression for each coexisting chronic conditions were: hypertension (1.22; 95% CI, 0.78-1.90), coronary artery disease (2.00; 95% CI, 1.27-3.14), chronic arthritis (2.02; 95% CI, 1.35-3.02), stroke (2.15; 95% CI, 1.10-4.31), chronic obstructive pulmonary disease (0.96; 95% CI, 0.52-1.81), and end-stage renal disease (1.19; 95% CI, 0.57-2.49). Conclusion: Odds of major depression are significantly increased among adults with diabetes in the presence of two or more coexisting chronic conditions, and coexistence of coronary artery disease, chronic arthritis, and stroke in particular, are associated with increased odds of major depression.