Prevalence of depression among type 2 diabetes compared to healthy non diabetic controls

Successful diabetes management depends on patient behaviour. Diabetes is a significant risk factor for depression which itself is a risk factor for poor metabolic control. Data on this association is scarce from India--which is fast becoming the diabetes capital of the world. This study was done to see the prevalence of depression in adult patients with type 2 diabetes diagnosed within the previous 5 years and treated with oral hypoglycaemic agents compared to healthy persons without diabetes. Also, to evaluate Becks depression inventory (BDI) in terms of Mini International Neuropsychiatric Interview (MINI) as a tool to assess depression in diabetes.

Patients with diabetes within 5 year of diagnosis and on oral anti-diabetic drugs were included. Controls were healthy relatives of these patients without diabetes. These patients underwent clinical examination, biochemical tests, assessment of depression by BDI and MINI BDI and MINI were used to assess depression in controls as well. Prevalence of depression was found in both groups and compared. BDI was evaluated considering the MINI as gold standard in detecting depression in diabetes.

The prevalence of co-morbid depression was 27.05% according to the MINI. In the non-diabetic healthy patient relatives, this was 11.11%. Those having depression had a lower educational attainment and a higher prevalence of retinopathy, compared to subjects without depression. The relative risk for the diabetics to have co-morbid depression was 2.97 (95% confidence interval 1.41-6.24). The BDI score with best sensitivity and specificity for diagnosing depression in diabetes was > or = 21. For healthy controls, a score of > or = 14 had best sensitivity and specificity. Diabetic patients had a higher score of BDI even without a diagnosis of depression on the MINI.

Prevalence of depression was 27.05% diabetic patients and 11.11% healthy controls. A BDI score of 21 had the best sensitivity and specificity for diagnosing depression in adult type 2 diabetic patients. BDI can be used as a simple screening tool for the detection of depression in diabetic patients.