Depressive symptoms in patients with type 2 diabetes in the ambulatory care setting: Opportunities to improve outcomes in the course of routine care

Objectives: To assess the frequency of untreated, self-reported depressive symptoms in a cross section of adult ambulatory patients with type 2 diabetes and to identify demographic and/or clinical characteristics associated with depressive symptoms in study patients. Design: Cross-sectional study. Setting: Three ambulatory care clinics in the southwestern United States in fall 2005. Patients: 217 primary care patients aged 18 years or older with a diagnosis of type 2 diabetes. Intervention: Administration of the Zung Self-rating Depression Scale (Zung SDS). Main outcomes measures: Self-reported data on demographic characteristics and depressive symptoms. Data for insurance, comorbid conditions, and glycosylated hemoglobin (A1C) values were abstracted from patient charts. Results: Depressive symptoms (Zung SDS score >= 50) were identified in 72.1% of patients. Overall, 13% of the patients with a diagnosis of depression (based on patient charts) were not receiving treatment. Factors significantly associated with depressive symptoms were past history of depression (beta = 0.53, P < 0.01), Medicaid insurance (beta = 0.15, P < 0.02), and insulin use (beta = 0.12, P < 0.05). Conclusion: The results suggest that possible undetected or untreated depression can be assessed in patients with type 2 diabetes through use of a self-rating scale in the course of routine ambulatory care. Adding the Zung SDS screen to routine care protocols could facilitate improved detection and treatment of comorbid depression in ambulatory patients with type 2 diabetes.