Placebo is not what you think it is

If I read one more crappy article about placebos, something’s gotta give, and it’s gonna be my head or my desk. Wired magazine has a new article entitled, “Placebos Are Getting More Effective. Drugmakers Are Desperate to Know Why.” Frequent readers of skeptical and medical blogs will spot the first problem: the insanely nonsensical claim that “placebos are getting better”. This not only “begs the question,” but actually betrays a fundamental misapprehension of the concept. I’ve written several times about the nature and ethical implications of placebos, but it’s time for a serious smackdown.

In clinical studies, “placebo” refers to a “treatment” which, compared with the test treatment, is inert. If I want to test a blood pressure pill for basic efficacy, I could simply give it to a group of people and see what their pressures are before and after taking the medicine. But that wouldn’t account for any blood pressure changes that occur simply from being part of the study or by chance alone. Such effects include paying better attention to one’s health and habits, trying to please the doctors, and other less clear and tangible effects.

So, to see what the real effect of the new pill is, it can be tested against a identical-appearing dummy pill, which we call “placebo”. Neither the experimenters nor the subjects know which pill is which. Then, the change in blood pressure between the real and placebo pill groups, and perhaps a no-pill group as well, can be compared to see if and to what extent the new pill lowers blood pressure; the key point being that this allows us to see how much of the blood pressure lowering effect is due to the new pill vs. other undefined factors be they random or due to being in a study.

The placebo “effect” is just that—an effect observed because of a particular situation. It does not show that there is some special benefit to sugar pills, but that when we observe people, we can measure changes that are not always due to our intended intervention. It is not possible to create strong or weak placebos, since the placebo effect is a measure of poorly defined effects and of chance alone. It is what it is.

The author of the Wired article doesn’t get it in a very profound way. I’ll give you a few laughable examples.

The fact that taking a faux drug can powerfully improve some people’s health–the so-called placebo effect–has long been considered an embarrassment to the serious practice of pharmacology.

Really? That’s not even wrong. Clinical pharmacology research depends on placebo controls to make sense of the data. The fact that certain data is affected in placebo groups does not, for example, mean everything we understand about the cytochrome P450 system is wrong.

He asserts that more and more drug studies are crapping out due to the placebo effect:

It’s not that the old meds are getting weaker, drug developers say. It’s as if the placebo effect is somehow getting stronger.

No, it’s not like that at all. Perhaps the studies are just that well done, or maybe the drugs being developed suck, or maybe companies are studying more candidate drugs and screening for efficacy. Just about any explanation that doesn’t involve aliens is better than “placebo is getting stronger”.

He goes on to talk about how placebo has become a crisis of the industry, but I have another explanation: it’s not “placebo” that’s the problem. If drugs in testing cannot outperform placebo, then the researches have done a good job of testing the drugs honestly. If the researchers are failing to develop drugs that beat placebo and the company’s bottom line is suffering, it’s not the fault of the sugar pill. Sometimes it’s either difficult or impossible to develop an effective medication. Failure is inevitable. It’s how science works. If the CEOs don’t like it, they have to either make up the data, or find a new business model.

Posted in: Science and Medicine

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