presumptions made by the medical profession, which make reassurance an increasingly outre business. A modern medic would struggle to find a form of words that would permit her to hand out a placebo, for example, and this is because of the difficulty in resolving two very different ethical principles: one is our obligation to heal our patients as effectively as we can; the other is our obligation not to tell them lies. In many cases the prohibition on reassurance and smoothing over worrying facts has been formalised, as the doctor and philosopher Raymond Tallis recently wrote, beyond what might be considered proportionate: ‘The drive to keep patients fully informed has led to exponential increases in the formal requirements for consent that only serve to confuse and frighten patients while delaying their access to needed medical attention.’
I don’t want to suggest for one moment that historically this was the wrong call. Surveys show that patients want their doctors to tell them the truth about diagnoses and treatments (although you have to take this kind of data with a pinch of salt, because surveys also say that doctors are the most trusted of all public figures, and journalists are the least trusted, but that doesn’t seem to be the lesson from the media’s MMR hoax).
What is odd, perhaps, is how the primacy of patient autonomy and informed consent over efficacy – which is what we’re talking about here – was presumed, but not actively discussed within the medical profession. Although the authoritative and paternalistic reassurance of the Victorian doctor who ‘blinds with science’ is a thing of the past in medicine, the success of the alternative therapy movement – whose practitioners mislead, mystify and blind their patients with sciencey-sounding ‘authoritative’ explanations, like the most patronising Victorian doctor imaginable – suggests that there may still be a market for that kind of approach.
About a hundred years ago, these ethical issues were carefully documented by a thoughtful native Canadian Indian called Quesalid. Quesalid was a sceptic: he thought shamanism was bunk, that it only worked through belief, and he went undercover to investigate this idea. He found a shaman who was willing to take him on, and learned all the tricks of the trade, including the classic performance piece where the healer hides a tuft of down in the corner of his mouth, and then, sucking and heaving, right at the peak of his healing ritual, brings it up, covered in blood from where he has discreetly bitten his lip, and solemnly presents it to the onlookers as a pathological specimen, extracted from the body of the afflicted patient.
Quesalid had proof of the fakery, he knew the trick as an insider, and was all set to expose those who carried it out; but as part of his training he had to do a bit of clinical work, and he was summoned by a family ‘who had dreamed of him as their saviour’ to see a patient in distress. He did the trick with the tuft, and was appalled, humbled and amazed to find that his patient got better.
Although he continued to maintain a healthy scepticism about most of his colleagues, Quesalid, to his own surprise perhaps, went on to have a long and productive career as a healer and shaman. The anthropologist Claude Levi-Strauss, in his paper ‘The Sorcerer and his Magic’, doesn’t quite know what to make of it: ‘but it is evident that he carries on his craft conscientiously, takes pride in his achievements, and warmly defends the technique of the bloody down against all rival schools. He seems to have completely lost sight of the fallaciousness of the technique which he had so disparaged at the beginning.’
Of course, it may not even be necessary to deceive your patient in order to maximise the placebo effect: a classic study from 1965 – albeit small and without a control group – gives a small hint of what might be possible here. They gave a pink placebo sugar pill three times a day to ‘neurotic’ patients, with good effect, and the explanation given to the patients was startlingly clear about what was going on:
A script was prepared and carefully enacted as follows: ‘Mr. Doe … we have a week between now and your next appointment, and we would like to do something to give you some relief from your symptoms. Many different kinds of tranquilizers and similar pills have been used for conditions such as yours, and many of them have helped. Many people with your kind of condition have also been helped by what are sometimes called ‘sugar pills’, and we feel that a so-called sugar pill may help you, too. Do you know what a sugar pill is? A sugar pill is a pill with no medicine in it at all. I think this pill will help you as it has helped so many others. Are you willing to try this pill?’
The patient was then given a supply of placebo in the form of pink capsules contained in a small bottle with a label showing the name of the Johns Hopkins Hospital. He was instructed to take the capsules quite regularly, one capsule three times a day at each meal time.
The patients improved considerably. I could go on, but this all sounds a bit wishy-washy: we all know that pain has a strong psychological component. What about the more robust stuff: something more counterintuitive, something more … sciencey?
Dr Stewart Wolf took the placebo effect to the limit. He took two women who were suffering with nausea and vomiting, one of them pregnant, and told them he had a treatment which would improve their symptoms. In fact he passed a tube down into their stomachs (so that they wouldn’t taste the revolting bitterness) and administered ipecac, a drug that which should actually
Not only did the patients’ symptoms improve, but their gastric contractions – which ipecac should worsen – were
More than molecules?
So is there any research from the basic science of the laboratory bench to explain what’s happening when we take a placebo? Well, here and there, yes, although they’re not easy experiments to do. It’s been shown, for example, that the effects of a real drug in the body can sometimes be induced by the placebo ‘version’, not only in humans, but also in animals. Most drugs for Parkinson’s disease work by increasing dopamine release: patients receiving a placebo treatment for Parkinson’s disease, for example, showed extra dopamine release in the brain.
Zubieta [2005] showed that subjects who are subjected to pain, and then given a placebo, release more endorphins than people who got nothing. (I feel duty bound to mention that I’m a bit dubious about this study, because the people on placebo also endured more painful stimuli, which is another reason why they might have had higher endorphins: consider this a small window into the wonderful world of interpreting uncertain data.)
If we delve further into theoretical work from the animal kingdom, we find that animals’ immune systems can be conditioned to respond to placebos, in exactly the same way that Pavlov’s dog began to salivate in response to the sound of a bell. Researchers have measured immune system changes in dogs using just flavoured sugar water, once that flavoured water has been associated with immunosuppression, by administering it repeatedly alongside cyclophosphamide, a drug that suppresses the immune system.
A similar effect has been demonstrated in humans, when the researchers gave healthy subjects a distinctively flavoured drink at the same time as cyclosporin A (a drug which measurably reduces your immune function). Once the association was set up with sufficient repetition, they found that the flavoured drink on its own could induce modest immune suppression. Researchers have even managed to elicit an association between sherbet and natural killer cell activity.
What does this all mean for you and me?
People have tended to think, rather pejoratively, that if your pain responds to a placebo, that means it’s ‘all in the mind’. From survey data, even doctors and nurses buy into this canard. An article from the
This is wrong. It’s no good trying to exempt yourself, and pretend that this is about other people, because we all respond to the placebo. Researchers have tried hard in experiments and surveys to characterise ‘placebo responders’, but the results overall come out like a horoscope that could apply to everybody: ‘placebo responders’ have been found to be more extroverted but more neurotic, more well-adjusted but more antagonistic, more socially skilled, more belligerent but more acquiescent, and so on. The placebo responder is everyman. You are a placebo responder. Your body plays tricks on your mind. You cannot be trusted.
How do we draw all this together? Moerman reframes the placebo effect as the ‘meaning response’: ‘the psychological and physiological effects of meaning in the treatment of illness’, and it’s a compelling model. He has also performed one of the most impressive quantitative analyses of the placebo effect, and how it changes with context, again on stomach ulcers. As we’ve said before, this is an excellent disease to study, because ulcers are prevalent and treatable, but most importantly because treatment success can be unambiguously recorded by having
