Are therapies like homeopathy or aromatherapy nothing more than elaborate placebos? If they work by some other mechanisms, what are they? And if they do work, does it really matter how they work?

In the scientific world, mechanism does matter. Without a plausible, testable mechanism, scientists are not impressed. That is why so many scientists are not convinced by homeopathy (where treatments are often so dilute that they are nothing more than water), or acupuncture (where there is no anatomical or physiological evidence for the “energy channels” on which the therapy depends). We hear from scientists and therapists who have tried to establish mechanisms for these therapies in formal experiments, and from practitioners who explain the importance – or otherwise – of understanding the “mechanisms”. Is there room for “alternative sciences”, such as those proposed by Lynn McTaggart, to explain the basis for CAM?

Dr Peter Fisher, president of the Faculty of Homeopathy, explains how homeopathy works in terms of an analogy - solutions hold a memory of the active substance just as video tapes hold pictures, so scientists analysing tape would only see iron particles, not images. Is it important, even if the effect is a type of placebo, for patients to have some image or concept in their mind of how the therapy is working? Why do some mainstream doctors, and others in the scientific community, get so worked up about mechanisms?

When doctors test a new treatment, they conclude that it works only when patients who receive it fare significantly better than those given a dummy treatment, or placebo. That’s because many patients feel better, no matter which one they receive. But having once written off the placebo effect as “no effect”, scientists are now discovering that the placebo effect can be very powerful indeed. Whatever the placebo effect really is, could it hold the secret mechanism for some complementary therapies? And if CAM is a sort of placebo, how do we explain the evidence that it can work in animals? We talk to one of the many vets who use CAM to treat their animal patients. And how do doctors who dismiss homeopathic remedies as “just water” explain the fact that trials show patients can often develop side effects?

We explore some of the latest biological theories which try to explain the placebo effect. Sir Ian Chalmers, past Director of the Cochrane Centre, explains that the size of the effect is determined by the way a patient and doctor interact, how a patient feels about their care, and what he or she is expecting from a therapy. And whether it’s conventional or alternative therapy, it’s now clear that patients and therapists need to believe that it will work. We also know that the more elaborate the therapy, the greater the effect. So with longer consultations and a more patient-centred, holistic approach, could it be that CAM therapies are simply tapping into this powerful placebo effect in a much more effective way than conventional medicine? And does that necessarily devalue it in some way? We ask patients, therapists, and sceptical physician Dr Roger Fisken, for their opinions.

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Content last updated: 08/09/2004