Trick or Treatment—The Undeniable Facts about Alternative Medicine (Electronic book text)

The placebo effect may be linked to either conditioning or expectation or both, and there may be other even more important mechanisms that have yet to be identified or fully appreciated. While scientists strive to establish the scientific basis of the placebo effect, they have already been able to ascertain, by building on Haygarth’s early work, how to maximize it. It is known, for instance, that a drug administered by injection has a bigger placebo effect than the same drug taken in pill form, and that taking two pills provokes a greater placebo response than taking just one. More surprisingly, green pills have the strongest placebo effect on relieving anxiety, whereas yellow pills work best for depression. Moreover, a pill’s placebo effect is increased if it is given by a doctor wearing a white coat, but it is reduced if it is administered by a doctor wearing a T-shirt, and it is even less effective if given by a nurse. Large tablets offer a stronger placebo effect than small tablets…unless the tablets are very, very small. Not surprisingly, tablets in fancy branded packaging give a bigger placebo effect than those in plain packets.

Of course, all of the above statements refer to the average patient, because the actual placebo effect for a particular patient depends entirely on the belief system and personal experiences of that individual. This variability of placebo effect among patients, and its potentially powerful influence on recovery, means that it can be a highly misleading factor when it comes to assessing the true efficacy of a treatment. In fact, the placebo effect is so unpredictable that it could easily distort the results of a clinical trial. Therefore, in order to test the true value of acupuncture (and medicines in general), researchers somehow needed to take into account the quirky, erratic and sometimes strong influence of the placebo effect. They would succeed in this endeavour by developing an almost foolproof form of the clinical trial.

The blind leading the double-blind

The simplest form of clinical trial involves a group of patients who receive a new treatment being compared against a group of similar patients who receive no treatment. Ideally there should be a large number of patients in each group and they should be randomly assigned. If the treated group then shows more signs of recovery on average than the untreated control group, then the new treatment is having a real impact…or is it?

We must now also consider the possibility that a treatment might have appeared to be effective in the trial, but only because of the placebo effect. In other words, the group of patients being actively treated might expect to recover simply because they are receiving some form of medical intervention, thus stimulating a beneficial placebo response. Hence, the straightforward trial design can produce misleading results, because even a useless treatment can give positive results in such a trial. So the question arises: how do we design a clinical trial that takes into account the confusion caused by the placebo effect?

A solution can be traced back to eighteenth-century France and the extraordinary claims of Franz Mesmer. Whilst Mesmer is nowadays associated with hypnotism (or mesmerism), in his own lifetime he was most famous for promoting the health benefits of magnetism. He argued that he could cure patients of many illnesses by manipulating their ‘animal magnetism’, and one of the ways of doing this was to give them magnetically treated water. The remedy was very dramatic, because sometimes the supposedly magnetized water could induce fits or fainting as part of the alleged healing process. Critics, however, doubted that water could be magnetized and they were also dubious about the notion that magnetism could affect human health. They suspected that the reactions of Mesmer’s patients were purely based on their faith in his claims. In modern parlance, critics were suggesting that Mesmer’s remedies were exploiting the placebo effect.

In 1785, Louis XVI convened a Royal Commission to test Mesmer’s claims. This Commission, which included Benjamin Franklin, conducted a series of experiments in which one mesmerized glass of water was placed among four glasses of plain water — all five glasses looked identical. Unaware which glass was which, volunteers then randomly picked one glass of water and drank it. In one case, a female patient tasted her glass and immediately fainted, but it was then revealed that she had drunk only plain water. It seemed obvious that the fainting woman thought that she was drinking magnetized water, she knew what was supposed to happen when people drank such water, and her body responded appropriately.