Clarification the optimal cut-off values for Persian-language versions of depression screening tools in Iranian patients with type 2 diabetes.

Background: Depression is the most common psychiatric disorder in patients with type 2 diabetes. There are many questionnaires to measure depression symptoms. These tools are generally used with the same cut-off points in different medical diseases. The present study investigates the optimal cut-off points of these tools in patients with type 2 diabetes in the Iranian diabetic population. The original version of this tool is prepared in Persian.

Methods: Two-hundred and forty four patients with a diagnosis of diabetes were selected to participate in the study. The gold standard for diagnosing depression was the Structured Mini-International Neuropsychiatric Interview. We applied the cut-off points of the Persian versions of the Hospital Anxiety and Depression Scale (HADS), Beck Depression Inventory (BDI), Depression in Diabetes Self-Rating Scale (DDS-RS), Problematic Areas in Diabetes Survey (PAID), Hamilton Depression Rating Scale (HDRS) and Depression in Diabetes Self-Rating Scale (DDS-RS).

Results: 23.8% of patients were diagnosed with depression. Depressed patients had higher levels of HbA1c and physical complaints than non-depressed patients. In all tools, the sum of Sensitivity and Specificity of our proposed cut-off points was better than the conventional cut-off points. In HADS, the results showed that this questionnaire performed better and more efficiently than other tools.

Conclusions: In patients with type 2 diabetes, it is better to use the proposed cut-off point's specific to this disorder in the Iranian population. These cut-off points have a higher ability to identify depressed and non-depressed cases.