Most of a typical homoeopath's caseload consists of chronic or recurrent conditions such as eczema, rheumatoid arthritis, fatigue disorders, asthma, migraine, dysmenorrhoea, irritable bowel syndrome, recurrent upper respiratory or urinary tract infections, and mood disorders. Homoeopaths also treat a substantial number of patients with ill defined illness that has not been given a conventional diagnosis. Children are much more commonly treated by homoeopaths than by other types of complementary practitioner.
Key studies of efficacy
- Kleijnen J, Knipschild P, ter Riet G. Clinical trials of homoeopathy. BMJ 1991;302:316-23
- Linde K, Clausius N, Ramirez G, Melchart D, Eitel F, Hedges LV, et al. Are the clinical effects of homeopathy placebo effects? A meta-analysis of placebo-controlled trials. Lancet 1997;350:834-43
Randomised controlled trials
- Reilly D, Taylor MA, Beattie NG, Campbell JH, McSharry C, Aitchison TC, et al. Is evidence for homoeopathy reproducible? Lancet 1994;344:1601-6
- Belon P, Cumps J, Ennis M, Mannaioni PF, Sainte-Laudy J, Roberfroid M, et al. Inhibition of human basophil degranulation by successive histamine dilutions: results of a European multi-centre trial. Inflamm Res 1999:48(suppl 1):S17-8
- Linde K, Jonas WB, Melchart D, Worku F, Wagner H, Eitel F. Critical review and meta-analysis of serial agitated dilutions in experimental toxicology. Hum Exp Toxicol 1994;13:481-92
Some homoeopaths say that few conditions are truly outside their remit, and the homoeopathic case literature includes treatment of complaints as diverse as tuberous sclerosis, infertility, myasthenia gravis, fear of flying, and cystic fibrosis. That said, opinions about what can be effectively treated by homoeopathy differ widely, even among homoeopaths, with medically trained practitioners generally being more conservative than non-medical ones. It is also used, often by self prescription, to treat various acute conditions such as the common cold, bruising, hay fever, and joint sprains.
Given the difficulties in understanding how homoeopathy may work, researchers have concentrated on establishing whether it is a placebo treatment. Current evidence suggests that this is probably not the case. A recent meta-analysis, published in the Lancet, examined over 100 randomised, placebo controlled trials and found an odds ratio of 2.45 (95% confidence interval 2.05 to 2.93) in favour of homoeopathy. The authors concluded that, even allowing for publication bias, “the results of our meta-analysis are not compatible with the hypothesis that the clinical effects of homoeopathy are completely due to placebo.”
The notorious Benveniste affair, which involved accusations of fraud and scientific misconduct after the publication of an in vitro experiment in Nature, continues to dampen enthusiasm for basic research in homoeopathy. None the less, laboratory studies have reported biological effects of homoeopathic medicines on animals, plants, and cells—some at ultramolecular dilutions.
Evidence is less clear on the effectiveness of homoeopathy as it is generally practised for the conditions that homoeopaths usually treat. Many trials have investigated treatment of an acute condition with a single remedy. This makes research easier but does not reflect the real world of homoeopathic clinical practice. For example, in the best known UK trial 144 patients with hay fever were randomised to receive either homoeopathically prepared grass pollen or placebo. Though there was a significant result in favour of homoeopathy, implications for clinical practice are unclear as most homoeopaths do not treat hay fever with homoeopathic grass pollen alone.
There is currently insufficient evidence that homoeopathy is clearly efficacious for any single clinical condition. For many of the conditions treated in homoeopathic practice—such as depression, fatigue, and eczema—randomised trials have not been undertaken. In addition, few of the existing studies of homoeopathy have been independently replicated.