The curious case of the placebo effect
Tricks the mind plays on the body
Homeopathy works. Just ask any believer and you will meet with a vociferous defence. They’ll tell you of ailments they had that homeopathy cured, and indeed the stories will check out. They actually had those ailments, and they actually got cured. Believers will tell you the science is real. The government assures you it is real—they certify homeopathic doctors.
But homeopathy is a pseudoscience. Large scale studies have found homeopathy to be no more effective than a placebo—a harmless substance like a sugar pill given to a patient who is not informed whether they are being given the medicine or the placebo. This is how medical drug tests are conducted—test subjects are divided into two groups, one of which gets the medicine and the other gets the placebo, except the subjects are not informed which group they are in. Medicines must perform demonstrably better than the placebo to be considered as medicine.
Homeopathy makes claims about how it works that dispute the foundations of modern science’s understanding of how the universe works. Some of those claims such as the “water memory effect” are outright bizarre—the claim went as far as to say that a homeopathic preparation could be delivered electronically over the internet. Wikipedia’s page on homeopathy is a comprehensive resource of the various claims, issues with them, and studies conducted. Also, contrast with vaccines, a system of medicine with a similar idea, that a weak dosage of the disease-causing agent can prevent (but not cure) the disease, which actually works.
And yet, faith in homeopathy runs strong. You no doubt know people who will say this is all fine, but they had some condition for which it really worked. How do you explain that?
To understand this better, it’s instructive to examine the other piece in this puzzle: the placebo, or specifically, something called the placebo effect. Test subjects who are told they are being given medicine and then given a harmless substitute somehow seem to get cured anyway, at a better rate than a control group of test subjects who are given no such assurance.
The placebo effect is widely accepted to be real, having been observed in multiple studies spanning decades, and yet researchers do not have a clear understanding of why it occurs, or of even how to reproduce it effectively. For this reason, it’s considered dangerous and unethical to use in medical treatment—assuring someone they will get cured does not guarantee at all the placebo effect will cure them. Patients must be given real medicine.
Last year, a review of 84 clinical drug trials (for chronic pain treatment) from 1990 to 2013 found something remarkable: the placebo effect is getting stronger — but only in the United States. Similar trials conducted elsewhere do not show the same effect. One hypothesis is that large scale, extended trials, which are common in the US, somehow increase the chances. Another is that public advertising for trials inviting consumers to participate may have something to do with it.
Could it be that homeopathy works for the faithful primarily because of their faith in it? That it is indeed the mysterious placebo effect and not homeopathy itself? Remember that multiple large scale studies have confirmed homeopathy does not work better than a placebo.
The lessons to take away from this:
- Faith is hard to reason with. Learn to recognise biases originating from faith rather than evidence.
- The placebo effect is not medicine. It does not work for everything, nor does it does work reliably. Your ailments need real medicine.
- The opposite of placebo is nocebo. Active mistrust of medicine may reduce its effectiveness. Ironically, this means real medicine works better if you believe in it.
- If a claim for some treatment defies a logical explanation, consider the possibility of the placebo effect combined with survival bias—you are only hearing the stories that survived. Someone believed in it and it worked for them, so their story propagates, while the others for whom it did not work are forgotten.
- There are many such cognitive and statistical biases that interfere with our ability to think through a situation properly. Being aware of these biases is the first step towards becoming aware that our reasoning may be biased.
Kilter is HasGeek’s humble attempt to provide a space for reasoned debate on how your body actually works, and how you can find your own path to good health via better nutrition, fitness and habits.
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