The underestimated power of the placebo

Dr Vernon Coleman MB ChB DSc

Note: The following essay is taken from a longer essay in the book 'Memories 3by Dr Vernon Coleman

Everyone has heard of witch doctors casting spells. It is well known, and well documented, that seemingly healthy individuals have died within weeks or even days of being cursed by a witch doctor of some kind. The power of the mind is difficult to under-estimate. A man or woman in a white coat can be, unwittingly, just as powerful as a witch doctor dressed in feathers and performing a mystical dance.

The word ‘placebo’ has been used since 1811 to denote a medicine given more to please than to benefit the patient. It is perhaps a rather unfair definition, for though the placebo may have no active effect it may nevertheless have a definite and useful psychological effect.

An alternative name sometimes used is ‘dummy tablet’ as the constituent of a placebo is traditionally nothing more than lactose or starch. As well as being used to treat patients, placebos can be used to test patients and to test other remedies. Sir William Gull, a 19th century physician who, annoyed and disturbed by claims for many treatments said to be useful for rheumatic fever, published a tongue in cheek paper extolling the virtues of mint as a cure. He selected mint at random but was amazed to see that his mint water treatment became fashionable and apparently effective.

At medical school I’d never heard the word ‘placebo’ mentioned and there certainly had not been any mention of the way that apparently powerless pills can have a useful, practical effect in medical practice. But, after I qualified, and my reading strayed outside the medical school curriculum, I read a great deal about placebos and started hunting through the medical journals for more examples of the effectiveness of this type of healing.

I found that the medical literature was absolutely full of references to placebo power. The science of the placebo had all really started, it seemed, during the Second World War when an American army medical officer had run out of morphine while treating injured soldiers. Rather than admit to the soldiers (many of whom were in terrible pain) that he had nothing to give them the doctor found some vials of plain water and gave those by injection. To his amazement the water proved to be as powerful a painkiller as morphine. The soldiers’ pains were eased though they’d been injected with nothing more powerful than water.

In the years which followed, the power of the placebo was investigated quite thoroughly by many experts. I found that placebos were used (knowingly or unknowingly) more often than any other drugs. They were often sneered at and their use was often dismissed as unethical. This seemed strange since they benefitted patients enormously and had few or no serious side effects.

In the Journal of Mental Science in 1957, Trouton wrote that for medical purposes placebos should be red, yellow or brown in colour, bitter in flavour, and either very large or very small. Another paper published in ‘Scientific American’ in 1955 came to the same conclusion. From other studies it was concluded that green tablets or capsules were better for depressed patients while yellow tablets or capsules were better for anxious patients. Capsules were usually found to be far more effective than tablets. And so I concluded that a large, green and yellow capsule should be ideal for most patients. It was, therefore, no coincidence that when I was a GP I regularly used a large, green and yellow capsule which contained a selection of harmless vitamins as a placebo. I had great success with it.

Work done in Liverpool in 1964 showed that many patients were dependent upon the shape of their tablets. Patients were given amphetamine tablets, placebo tablets shaped like amphetamines and an amphetamine of a different shape. The placebo shaped like the amphetamine seemed to be better than the amphetamine which did not look like an amphetamine.

The efficiency of placebos can be startling. It has been shown that 30% of patients with severe, steady post-operative pain get relief from placebos. From this information it is clear that the effectiveness of a drug must be the effectiveness of the inactive qualities of the drug plus the effectiveness of the active part. No less than fifteen different studies on 1,082 patients have shown that placebos have an average effectiveness of 35% when given to patients with pains (including angina and headache) and nausea and with psychological problems such as anxiety. Any new drug which has a less than 30% effectiveness is no better than a placebo.

As Knowles and Lucas wrote in the ‘Journal of Mental Science’ in 1960: ‘The placebo response may well be an important component of many established treatments both physical and psychological and does in itself constitute a means of therapy’.

According to the ‘British Medical Journal’ in 1970: ‘60% of patients were found to experience an appreciable reduction in the frequency of attacks of angina by means of suggestion and placebos were as effective as 30mg of codeine in inhibiting the cough reflex’. Other reports have suggested that as many as 40% of all the mentally ill may respond to placebos. According to one British GP, seven out of ten British doctors prescribe placebos for unhappiness. Family doctors in Britain have estimated that up to a third of their patients have nothing wrong with them and are simply unhappy. Other GPs reported that up to two thirds of all the patients they see have nothing physically wrong with them.

That gives some idea of the extent and importance of placebo prescribing. It has been reliably estimated that 30 to 40% of NHS prescriptions are, effectively, for placebos even if neither the patient nor the prescribing doctor is aware of this. Sadly, drugs such as benzodiazepines are often prescribed as though they are placebos – when they most certainly are not.

It is of course a prerequisite of the placebo prescriber that the patient should believe in him and the treatment he prescribes. If the prescriber does not clearly seem to have faith in the drug he prescribes, then the patient will be unlikely to respond favourably. Even more important perhaps is the image of the whole medical profession.

What is perhaps rather worrying is the fact that so many drug companies seem to be advertising and marketing products which do not even have the level of success one would expect with a placebo. If a placebo has a 30% to 40% activity, any pharmacologically active product should be better than that. Some studies have been published showing a placebo result of only ten to fifteen per cent, compared with which the drug under test did well. In such trials one must be suspicious of the techniques employed.

Recent studies have shown that some widely prescribed anti-depressant drugs (which invariably may have horrendous side effects) are notably less effective than a placebo.

And there has even been research which has shown that patients with heart disease, who had been considered suitable subjects for open heart surgery, recovered after going through an operation in which all that happened was that their chests were cut open and then stitched up again. The surgeon didn’t touch the heart at all but the patients improved massively and because they hadn’t been through the trauma of open heart surgery they recovered far more speedily. That’s how powerful the placebo response can be!

A study of 200 patients, some of whom had stents put in to help them deal with angina and some of whom only thought they’d had stents put in, found that the placebo group were just as well after their non-existent surgery as the patients who had had (potentially dangerous and debilitating) surgery.

Another experiment, reported in the ‘New England Journal of Medicine’ in 2014, involved patients who had knee surgery for the repair of a torn meniscus. Half of the patients had actual surgery done to repair the tear and the other half of the patients went through a fake procedure. They were taken into the operating theatre and anaesthetised and bandaged but no operation was performed. The two groups recovered equally well. The surgery was of no real value whatsoever.

A review published in the ‘British Medical Journal’ studied 53 clinical trials which compared the results of real surgery with placebo surgery. In 39 of the trials the placebo group noted improvements and in 27 of the trials the results for the patients who had ‘real’ surgery were no better than the results for the patients who had no surgery at all – but who thought they had been operated on. It is clear from this work that much surgery (which comes with considerable risks, of course) is unnecessary and, indeed, unethical.

And then there is the equally solid evidence showing that the way a doctor talks to a patient can have a tremendous effect on the result of the treatment he offers. The doctor in a white coat can have just as powerful an effect on a patient as the witch doctor in a startling feather based costume. If a doctor convinces a patient that the treatment he is offering will work then the chances are much higher that the treatment will work.

As I pointed out in my book Mindpower, although the colour, shape and size of a placebo tablet affects its efficacy, nothing governs the power of a placebo quite so much as the enthusiasm with which it is offered to the patient.

So, if a doctor gives a patient a placebo tablet and says something like: ‘Try this, it might help you a little’, the chances of the placebo working are relatively slight.

If, however, the doctor hands over the placebo tablet with an enthusiastic comment such as, ‘Take this. It’s the most powerful and effective drug on the market. It will help you’, the chances of the placebo working are increased enormously.

It is even possible for doctors to influence the sort of side-effects patients are likely to get simply by what they say.

So, if a doctor handing over a pill (whether or not it is a placebo pill) says: ‘Watch out. This pill may produce a rash and make you feel drowsy’, the chances are very high that the patient will complain that the pill makes him feel drowsy and gives him a rash. Our bodies respond, it seems, not simply to what is in a tablet but to what we expect it to contain.

Nor is it just tablets and pills and drugs that operate the placebo effect. We associate the placebo effect with pills simply because we associate doctors with pills, but in fact the placebo effect can work in a thousand other ways too.

So, for example, if a surgeon who is about to operate on a patient says, ‘I’m afraid that when you wake up you’ll be in a lot of pain and probably rolling around in agony’, the patient will probably wake up in a good deal of pain. (That sounds like a silly thing for any surgeon to say but I’ve known it done.)

Whereas if a surgeon who is about to operate on a patient says something like, ‘When you wake up you will feel much better and calmer and we will make sure that you do not suffer any pain’, the patient will probably wake up free of pain and discomfort – whether or not they are given painkillers.

To give another example, if a doctor sees a patient who complains of a pain in his neck and says, ‘I can help get rid of that pain for you with a little massage’, the patient’s pain will quite probably disappear after a little massage. It probably won’t be the massage that will have got rid of the pain. It will be the fact that the doctor has promised the patient a cure.

By now, of course, it should be fairly clear that if a doctor can have this ‘healing’ effect, there is nothing at all to stop non-qualified practitioners from producing a similar effect. And that, of course, is just what happens. Many of the alternative practitioners who have a remarkably high degree of success with patients depend very much on the placebo effect. They help their patients get better by being enthusiastic and optimistic.

In order to create the placebo effect, nurses and doctors need quiet self-assurance that is built on confidence and transmits relief and hope to the patient. But too many of today’s medical professions exude instead the self-satisfied arrogance that is more traditionally associated with investment bankers and barristers.

These days the use of placebos is frowned on by the medical establishment and by many who claim to represent patients’ interests. The reason is quite obvious: placebos tend be generic or very cheap and nowhere near as profitable as many of the drugs they can be used to replace. The fact that placebos are often far more effective than infinitely more expensive and dangerous products is of no interest to the medical establishment which was long ago bought, lock stock and syringe barrel, by the pharmaceutical industry.

Why is it ethical to prescribe a potential dangerous drug which produces a mass of unpleasant side effects and can kill, and which has, maybe, a 2% chance of improving a patient’s condition, but unethical to prescribe a safe medicine which is incredibly unlikely to do any lasting harm (though even placebos can inspire temporary side effects) but is pretty well guaranteed to produce an uplift in the patient’s health of 30% or even more?

When I was working as a GP I regularly used placebos and I had tremendous success with the ones I use and successfully managed to treat a number of patients who were suffering with anxiety and depression. If I were young enough to go back into practice today, I would use placebos regularly.

I even found that it was possible to use a placebo to counteract the very real side effects associated with some medication. So, for example, a patient who needed to take a medicine which caused terrible nausea was cured of the nausea when I added a placebo to her therapeutic regimen. That’s another advantage of the placebo. You can give it together with other medicines without having to worry about there being an adverse interaction.


This short article was taken from a longer essay in the book `Memories 3’ by Vernon Coleman. Memories 3 is, [the last one] of three books of Vernon Coleman’s reminiscences. The other volumes are Memories 1 and Memories 2. You can purchase a copy of `Memories 3’ and the other two books in the series via the bookshop HERE. Copyright Vernon Coleman February 2024


Source: Vernon Coleman. Image: © N/A; Experience Life. AWIP:


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