BACKGROUND: Major depressive disorder has been shown to affect many domains of family life including family functioning. Conversely, the influence of the family on the course of the depression, including the risk of relapse, is one reason for targeting the family in interventions. The few studies conducted within this area indicate that family psychoeducation as a supplement to traditional treatment can effectively reduce the risk of relapse in patients with major depression as well as being beneficial for the relatives involved. However, the evidence is currently limited. This study will investigate the effect of family psychoeducation compared to social support on the course of the illness in patients with major depressive disorder.

METHOD/DESIGN: The study is designed as a dual center, two-armed, observer-blinded, randomized controlled trial. Relatives are randomized to participate in one of two conditions: either four sessions of manualized family psychoeducation or four sessions in a social support group led by a health care professional. Patients will not participate in the groups and will continue their treatment as usual. A total of 100 patients, each accompanied by one relative, will be recruited primarily from two outpatient clinics in the Capital Region of Denmark. The primary outcome is the occurrence of depressive relapse at 9-month follow-up defined as a score ≥7 on the Hamilton six-item subscale. Secondary outcomes will include time to relapse.

DISCUSSION: It is hoped that the results from this study will help to clarify the mechanisms behind any beneficial changes due to family psychoeducation and provide information on the long-term effect of this intervention for both patient and relatives. If the results are positive, the family psychoeducation program may be suitable for implementation within a clinical setting.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02348827 , registered 5 January 2015.