Take this. You'll feel better

Observations on placebos

The recent Lancet report which claimed that homoeopathic remedies are no better than placebos brought the school of common sense out in a rash of triumphalist scorn. Didn't we tell you so? Mumbo-jumbo. All in the mind.

Yet the research raises more profound questions than have hitherto been addressed in opinion columns. When people are told something is "all in the mind" or "psychological", they are offended, feeling stigmatised, accused of illusory symptoms or, worse, of flabby moral fibre and even faking illness. Most people's perception of the mind is a nebulous aura, separate from but linked to the serpiginous pudding that is the brain; something like the soul of the brain; a spiritual domain where resides that wonderful element called free will.

Yet modern brain research increasingly shows that emotions, impressions, symptoms, decisions are registered as physical events in the grey-white matter. The brain, in other words, is the mind, and our growing understanding of it erodes the concept of free will.

People in power and positions of influence who fall for the superstitious and the portentous tend to be mocked. The Blairs, Beckhams and McCartneys dabble in weird remedies, while top sportspeople rely on talismans, from nasal strips to titanium charms, to give them an edge. Perhaps we need to think about this more seriously. After all, medicine has only in recent decades tried to acquire an evidence base, while shamanism held our forebears in fear, hope and amazement for millennia. It is not illogical to wonder if we are evolutionarily selected to believe the crazy rather than the rational - and to derive a healing benefit from it.

The placebo effect seems to be strongest for the symptom of pain. When a person believes pain is about to be relieved by a pill or an injection, the brain is prompted to release its own endorphins, or opiate-like analgesic chemicals. This can be seen in volunteers exposed to painful stimuli while undergoing PET (positron emission tomography) brain scans. The researchers follow the intensity of the pain on the scan. When subjects are given a placebo they are told is a pain reliever, the signals of the pain's intensity diminish, though the effect is stronger in some subjects than in others.

When a placebo is administered for pain management, the course of pain relief is as one would expect for an active drug - that is, it peaks an hour afterwards and then declines. These responses are among the strongest pieces of evidence for the validity of the placebo effect.

Pain, being subjective, has always been hard to prove or measure, but other studies have used readily measurable parameters, to striking effect. Doctors painted warts with a brightly coloured, inert dye and assured the patients the lesions would vanish as the colour wore off; and they did. In asthmatics, telling sufferers that they were inhaling a bronchodilator brought about opening of airways. Patients with colitis treated with placebos had visible improvement of their inflamed intestines.

The placebo effect may sometimes depend on the therapist as well as the patient believing in the efficacy of the treatment, but it is clear that the response is not just in the mind but in the body, too. Just what neurochemicals the brain is able to rustle up to dissolve warts is anybody's guess.

Throughout history and literature, there persists a cogent set of observations that those of sanguine and optimistic temperaments have tended to overcome illness better than others of gloomy outlook. We may have whole medicine chests evolved in our skulls.

Modern medicine is replacing an old belief system, and has undoubtedly achieved solid therapeutic advances. Yet the immense range of pharmaceuticals do not work in one-third of people, we hear. One may speculate whether they are the same people who respond suboptimally to placebos.

In the west, we seem addicted to pill-popping, yet we know that the pharmaceutical industry wields its power in great measure through fear and deception. A reincarnation, perhaps, of the cult of witch doctors.