Limited effect of screening for depression with written feedback in outpatients with diabetes mellitus: a randomised controlled trial

The aim of this study was to test the effectiveness of a screening procedure for depression (SCR) vs care as usual (CAU) in outpatients with diabetes. The primary outcome measured was depression score and the secondary outcomes were mental healthcare consumption, diabetes-distress and HbA(1c). In a multicentre parallel randomised controlled trial, 223 outpatients with diabetes, who had an elevated depression score, were randomly assigned to SCR (n = 116) or CAU (n = 107), using computer generated numbers. SCR-patients were invited for a Composite International Diagnostic Interview (CIDI) to diagnose depression and/or anxiety (interviewers were not blinded for group assignment). As part of the intervention, patients and their physicians were informed of the outcome of the CIDI in a letter and provided with treatment advice. At baseline and 6 month follow-up, depression and diabetes-distress were measured using the Centre for Epidemiologic Studies Depression Scale (CES-D) and the Problem Areas in Diabetes survey (PAID). HbA(1c) levels were obtained from medical charts. Mean CES-D depression scores decreased from baseline to 6 months in both groups (24 +/- 8 to 21 +/- 8 [CAU] and 26 +/- 7 to 22 +/- 10 [SCR] respectively [p < 0.001]), with no significant differences between groups. Neither diabetes-distress nor HbA(1c) changed significantly within and between groups. The percentage of patients receiving mental healthcare increased in the SCR group from 20% to 28%, compared with 15% to 18% in the CAU group. Depression screening with written feedback to patient and physician does not improve depression scores and has a limited impact on mental healthcare utilisation, compared with CAU. It appears that more intensive depression management is required to improve depression outcomes in patients with diabetes.