Depressed patients treated by homeopaths: a randomised controlled trial using the “cohort multiple randomised controlled trial” (cmRCT) design

BACKGROUND: Despite controversy regarding homeopathy, some patients consult homeopaths for depression. Evidence is required to determine whether this is an effective, acceptable and safe intervention for these patients. METHODS: A pragmatic trial using the “cohort multiple randomised controlled trial” design was used to test the effectiveness of adjunctive treatment by homeopaths compared to usual care alone, over a period of 12 months in patients with self-reported depression. One third of patients were randomly selected for an offer of treatment provided by a homeopath. The primary outcome measure was the Patient Health Questionnaire (PHQ-9) at 6 months. Secondary outcomes included depression scores at 12 months; and the Generalised Anxiety Disorder (GAD-7) outcome at 6 and 12 months. RESULTS: The trial over-recruited by 17% with a total of 566 patients. Forty percent took up the offer and received treatment. An intention-to-treat analysis of the offer group at 6 months reported a 1.4-point lower mean depression score than the no offer group (95% CI 0.2, 2.5, p = 0.019), with a small standardized treatment effect size (d = 0.30). Using instrumental variables analysis, a moderate treatment effect size in favour of those treated was found (d = 0.57) with a between group difference of 2.6 points (95% CI 0.5, 4.7, p = 0.018). Results were maintained at 12 months. Secondary analyses showed similar results. Similar results were found for anxiety (GAD-7). No evidence suggested any important risk involved with the intervention. CONCLUSION: This trial provides preliminary support for both the acceptability and the effectiveness of treatment by a homeopath for patients with self-reported depression. Our results provide support for further pragmatic research to provide more precise estimates of treatment effect. TRIAL REGISTRATION: ISRCTN registry, ISRCTN02484593. Registered on 7 January 2013. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13063-017-2040-2) contains supplementary material, which is available to authorized users.