Prevalence of depression in type 2 diabetes mellitus

The relationship between depression and diabetes has been widely documented but there have been methodological limitations such as the failure to conduct a diagnostic interview of the depressive condition. We have estimated the prevalence of depression in patients with type 2 diabetes mellitus (DM2) and its relationship with sociodemographic, lifestyle and clinical variables.

This was a cross-sectional, randomized study (stratified by sex and age) of patients with DM2 treated in a healthcare area with approximately 3000 eligible patients. The depressive symptoms were assessed using the Beck Depression Inventory (depression defined as a BDI score>16) and a psychiatric interview. We used a multivariate logistic regression model to evaluate the association between depression and DM2, after adjusting for known risk factors.

We examined 275 patients with DM2 (mean age, 64.5 years; men, 56.4%). The prevalence of depression was calculated at 32.7% (95% CI 27.4-38.5) and increased with age. A greater prevalence of depression was found in women, widowers, patients with obesity, those with poor compliance with the prescription, those with poor glycemic control and those who developed complications from diabetes. Thirty-five percent (95% CI 26.4-45.8) of the patients who scored>16 on the BDI scale had not been diagnosed with depression.

Depression is highly prevalent in patients with DM2, especially in women. For approximately one-third of the patients, a diagnosis of depression had not been reached.