The comorbidity of diabetes mellitus and depression.

Several factors, including sedentary lifestyle, obesity, and an aging population, contribute to epidemic rates of type 2 diabetes mellitus. Depression frequently occurs comorbidly with diabetes although it is unrecognized and untreated in approximately two thirds of patients with both conditions. The course of depression in patients with both diabetes and depression is chronic and severe. Up to 80% of patients with diabetes and depression will experience a relapse of depressive symptoms over a 5-year period. Depression is associated with nonadherence to diabetes self-care--including following dietary restrictions, medication compliance, and blood glucose monitoring--resulting in worse overall clinical outcomes. Due to potential negative health consequences associated with comorbid diabetes and depression, both conditions should be optimally treated to maximize patient outcomes.