The Prevalence and Specificity of Depression Diagnosis in a Clinic-Based Population of Adults With Type 2 Diabetes Mellitus

Objective To estimate the crude prevalence of minor depressive disorder (MinD) in a clinic-based population of adults with type 2 diabetes. Methods We screened a clinical sample of 702 adults with type 2 diabetes for depressive symptoms using the Patient Health Questionnaire-2 and performed a structured diagnostic psychiatric interview on 52 screen-positive and a convenience sample of 51 screen-negative individuals. Depressive disorder diagnoses were made using Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) Text Revised criteria and categorized as MinD, major depressive disorder (MDD), or no depressive disorder. We estimated prevalence of MinD and MDD and derived 95% CIs. Results The crude prevalence of current, past, and current or past MinD was 4.3% (95% CI: 0.9–9.2%), 9.6% (95% CI: 3.9–15.9%), and 13.9% (95% CI: 7.7–21.2%), respectively. The crude prevalence of current, past, and current or past MDD was slightly higher—5.0% (95% CI: 1.9–9.4%), 12.0% (95% CI: 6.1–19.5%), and 17.0% (95% CI: 10.1–24.8%), respectively. There was a high prevalence of coexisting anxiety disorders in individuals with MinD (42.2%) and MDD (8.1%). Hemoglobin A1c levels were not significantly different in individuals with MinD or MDD compared to those without a depressive disorder. Conclusions MinD is comparably prevalent to MDD in patients with type 2 diabetes; both disorders are associated with concomitant anxiety disorders. MinD is not included in the DSM-5; however, our data support continuing to examine patients with chronic medical conditions for MinD.