ABSTRACT

Introduction: Depression is a common reason for patients to consult homeopaths. This review aims to assess the efficacy, effectiveness and safety of homeopathy in depression. Methods: Thirty databases/sources used to identify studies reporting on homeopathy in depression, published between 1982 and 2016. Studies were assessed for their risk of bias, model validity, aspect of homeopathy and comparator. Results: Eighteen studies assessing homeopathy in depression were identified. Two double-blind placebo-controlled trials of homeopathic medicinal products (HMPs) for depression were identified. The first trial (N=91) with high risk of bias found HMPs were non-inferior to fluoxetine at 4 (p=0.654) and 8 weeks (p=0.965); whereas the second trial (N=133), with low risk of bias, found HMPs was comparable to fluoxetine (p=0.082) and superior to placebo (p<0.005) at 6 weeks. The remaining research had unclear/high risk of bias. A non-placebo-controlled RCT found standardised treatment by homeopaths comparable to fluvoxamine; a cohort study of patients receiving treatment provided by GPs practising homeopathy reported significantly lower consumption of psychotropic drugs and improved depression; and patient-reported outcomes showed at least moderate improvement in 10 of 12 uncontrolled studies. Fourteen titles provided safety data. All adverse events were mild or moderate, and transient. No evidence suggested treatment was unsafe. Conclusions: Limited evidence from two placebo-controlled double-blinded trials suggests HMPs might be comparable to antidepressants and superior to placebo in depression, and patients treated by homeopaths report improvement in depression. Overall, the evidence gives a potentially promising risk benefit ratio. There is a need for additional high quality studies.

INTRODUCTION

Depression is the third most common burden of disease worldwide and is expected to become the leading burden of disease by 2030 [1]. The National Institute for Health and Clinical Excellence primarily recommends non-medical interventions such as cognitive behavioural therapy in subthreshold, mild and moderate depression as the first line treatment [2]. If these interventions are ineffective or the depression is severe, antidepressant drugs are recommended. These treatment options help some but not all patients, there is concern about the overuse of psychotropic drugs, and insufficient alternatives. Some patients seek complementary and alternative medicine (CAM) treatment options, and depression and other mental health problems are among the most common reasons why patients seek homeopathy [3,4]. Homeopathy is controversial in some quarters, but despite this there is widespread use. A recent systematic review of 12-month prevalence of homeopathy use in eleven countries (USA, UK, Australia, Israel, Canada, Switzerland, Norway, Germany, South Korea, Japan and Singapore) found that a small but significant percentage of these general populations consulted homeopaths and/or purchased over-the-counter homeopathic medicines [5]. According to the MeSH term (E02.190.388) homeopathy is “a system of therapeutics founded by Samuel Hahnemann (1755-1843), based on the Law of Similars where ‘like cures like’. Diseases are treated by highly diluted substances that cause, in healthy persons, symptoms like those of the disease to be treated.” These substances, which are referred to as Homeopathic Medicinal Products (HMPs), are regulated through European Directives for medicinal products [6]. Treatment by homeopaths involves consultations and subsequent prescription of individually tailored HMPs based on information obtained during consultations. Standardised medicines for clinical complaints also exist. There is a need to assess the existing research evidence for homeopathy in depression due to the prevalence of depression in all countries worldwide, the limited effect of existing recommended interventions, and the fact that patients use homeopathy as an alternative or a complement to conventional treatment. One systematic review assessing research evidence for homeopathy in depression concluded that there was limited evidence due to a lack of high quality trials [7]. Another review on homeopathy in psychiatric conditions, which included only randomised placebo-controlled trials found none reporting on depression [8]. The aim of this review is to update these previous reviews and to assess the evidence for the efficacy, effectiveness and safety of homeopathy in patients with depression. The first draft of this updated review was published in the first author’s (PV) PhD Thesis [9]. This article presents the results of our updated review.