麻豆区

If I told you that an all-natural remedy performed just as well as a placebo in a clinical trial, how would you interpret that?

Proponents of so-called complementary and alternative medicine often clamour for large clinical trials to be done of their interventions like homeopathy and acupuncture and criticize the lack of money to conduct these studies. Very often, however, these studies have been conducted, but because the results were disappointing, they are easily swept under the carpet and wiped from their memory.

But we have seen a worrying trend in those communities in the last decade or so. When the studied treatment performs no better than a placebo, it is now said to be working through the placebo effect. Homeopathy fails to show superiority compared to placebo? It鈥檚 not that it didn鈥檛 work; it鈥檚 that it tapped into the magical placebo effect, and that is how participants were healed.

Likewise, when the placebo effect is discussed in the media, it is often simplified into the question of whether or not the brain can be tricked into healing the body. But that misses the actual reason why we have placebo arms in our best clinical trials: to eliminate effects that are not caused by the treatment being tested.

If we鈥檙e investigating a new treatment for the flu, our research participants will eventually start to feel better because the flu, unless it kills you, is a self-limiting illness. Participants in the placebo arm of the trial don鈥檛 get better because their mind was tricked by a sugar pill. Their immune system simply kicked in, just as it would have kicked in had they not participated in this trial. This improvement in the placebo arm of a trial is known as the placebo response.

Likewise, symptoms fluctuate. When you are asked to rate your symptoms at the beginning of the trial, they might be really bad, but when you鈥檙e asked again two weeks later, they might have abated because things like pain and nausea have ups and downs. Again, it鈥檚 not the sugar pill that tricked your brain; it鈥檚 just the natural course of your symptoms.

We should really speak of 鈥減lacebo effects,鈥� plural, as a collection of non-specific effects that have nothing to do with the active ingredient in the treatment we are interested in and which contribute to the placebo response.

Patients might give the answer that is expected of them to please the doctor. For example, if you鈥檝e enrolled in a clinical trial and have been told this new drug is very promising to treat pain, and you鈥檙e asked if your pain has improved, you might not be 100% objective in your assessment: you may want to please the doctor. And if you鈥檙e asked how much better you feel at the end of the trial compared to the beginning of the trial, you may misremember how you felt when this whole thing started, which skews your assessment. You might also be taking other drugs that are actually having an effect. A good clinical trial would control for that, but not all trials are created equal.

The reason why clinical trials tend to have a placebo arm is precisely to shave away all of these non-specific effects until all that is left is the specific effect of the active ingredient. If the treatment performs no better than placebo, it does not work.

There might still be an effect of the mind over the body, especially when it comes to subjective symptoms like pain and nausea, but we should never assume that it is the correct explanation before we have ruled everything else out. When Drs. Hr贸bjartsson and G酶tzsche examined that contained both a placebo arm and a no-treatment arm, they could not find any reliable placebo effect when what was measured was objective (like a test administered by a doctor), only a small effect when the measurement was subjective (like a questionnaire asking a patient how bad their pain is today). The claim that the placebo effect is powerful is quite simply a myth.

But what do you do when your multibillion-dollar industry is predicated on your magical treatment working? You reinterpret this finding and say that it works through the magic of the all-powerful placebo effect.

In the mid-2000s, a simple product entered the zeitgeist: ShamWow. Named after the pliable leather chamois cloth, ShamWow was the brainchild of , an amateur filmmaker who had seen poorly advertised absorbent cloths and wanted to make one with better marketing. The were simple and in your face, with Vince looking like Michael Shannon鈥檚 loud, younger brother confidently telling you that ShamWow can hold twenty times its weight in liquid. ShamWow was more than just a product; it was a meme.

This idea that an intervention works through the placebo effect because it performed as well as the placebo arm of a trial? It should have a name. Placebos are often referred to as 鈥渟hams,鈥� because they are pretenses. They are meant to look real even though they lack an active ingredient.

The ShamWow fallacy is the mistake we make when we look at the results of a study in which the intervention arm and the placebo arm are neck and neck, and we declare that the intervention must be working through the placebo effect. 鈥淛ust as good as the sham?鈥� we ask ourselves. 鈥淲ow! That must mean it鈥檚 working through the magic of the placebo effect!鈥�

I don鈥檛 know if the name will be absorbed by our collective minds, but I鈥檝e heard that ShamWow is really, really absorbent.