International guidelines advocate depression screening in patients with coronary heart disease (CHD) and other chronic illnesses, but evidence is lacking.

To test the differential efficacy of written patient-targeted feedback v. no written patient feedback after depression screening.

Patients with CHD or hypertension from three cardiology settings were randomised and screened for depression (ClinicalTrials.gov Identifier: NCT01879111). Compared with the control group, where only cardiologists received written feedback, in the intervention group both cardiologists and patients received written feedback regarding depression status. Depression severity was measured 1 month (primary outcome) and 6 months after screening.

The control group (n = 220) and the patient-feedback group (n = 155) did not differ in depression severity 1 month after screening. Six months after screening, the patient-feedback group showed significantly greater improvements in depression severity and was twice as likely to seek information about depression compared with the control group.

Patient-targeted feedback in addition to screening has a significant but small effect on depression severity after 6 months and may encourage patients to take an active role in the self-management of depression.