Positive association between serious psychiatric outcomes and complications of diabetes mellitus in patients with depressive disorders

Objectives: Depression and diabetes are closely biologically and behaviorally intertwined. We examined the impact of comorbid diabetes mellitus on the incidence of serious psychiatric outcomes among patients with depression. Methods: We used claims data from the Korean Health Insurance Review and Assessment Service database of patients who were diagnosed with depression within one year of an index prescription for antidepressants between January 2007 and June 2008. We investigated the association between the comorbidity of diabetes mellitus and serious psychiatric outcomes of depression, such as psychiatric hospitalization, psychiatric emergency room visits, and suicide attempts. Results: Among 200,936 patients with depression, 74,160 (36.9%) had diabetes mellitus, including 57,418 (28.6%) with complications. The incidence of serious psychiatric outcomes was 3.3% in patients with depression without diabetes and 6.7% in patients with depression and diabetes mellitus. Patients with depression and diabetes mellitus complications showed higher rates of serious outcomes than that did those without diabetes mellitus complications (odds ratio, 1.19; 95% confidence interval, 1.11-1.13). Similarly, depressed patients with micro and macrovascular diabetic complications were more likely to experience serious outcomes than those without diabetes mellitus complications (odds ratio, 2.2; 95% confidence interval, 2.07-2.34). Conclusions: Our results showed that comorbid diabetes mellitus can increase the risk of serious outcomes of depression, such as suicide and hospitalization, and thus may alter the antidepressants prescription patterns and healthcare service use among patients with depressive disorders.