Placebos without deception still work


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One of my greatest regrets about writing this blog is that the more I dig into the evidence behind most of the supposed “performance-boosting” supplements out there, the less I believe most of them have any legitimate effect. If I never looked at the actual research, I could be popping all sorts of pills in blissful ignorance — and because I’d believe in them, they’d give me a nice robust placebo effect. In fact, I’ve toyed (mostly in jest) with the idea of suggesting that elite athletes should avoid finding out too much about the science of ergogenics, so that they can maintain the fantasy that these things work and thus get an edge from them.

But a recent study from Harvard suggests that one of my key assumptions may be false. The study (which is freely available here and described by a press release here) set out to determine whether you have to believe in a placebo in order for it to work. To that end, they recruited 80 patients with irritable bowel syndrome (IBS). Half of them received no treatment, while the other half received placebo pills to take twice daily — but they knew that the pills were nothing but sugar:

“Not only did we make it absolutely clear that these pills had no active ingredient and were made from inert substances, but we actually had ‘placebo’ printed on the bottle,” says Kaptchuk. “We told the patients that they didn’t have to even believe in the placebo effect. Just take the pills.”

To everyone’s surprise, nearly twice as many placebo patients reported relief from their symptoms (59% vs. 35%), and “patients taking the placebo doubled their rates of improvement to a degree roughly equivalent to the effects of the most powerful IBS medications.”

So what on earth is going on here? The researchers speculate that “there may be significant benefit to the very performance of medical ritual.” This isn’t a new idea — I read a very interesting book on the placebo effect a few years ago that argued, in effect, that the doctor-patient relationship is the most powerful placebo mechanism available to us. Of course, “feeling better” is not the same kind of outcome as “running faster” or “growing bigger muscles.” I’d love to see a study that investigated whether undisguised sugar pills could enhance athletic performance. What would WADA do if the results came back positive? 🙂

9 Replies to “Placebos without deception still work”

  1. I was interested by this study too. I’m a bit uncomfortable with their advertising that was used to seek out participants though because I think it might have self-selected for people who believe in woo. And I also wonder whether people understood what a sugar-pill or placebo really was, and am worried that people who believe in homeopathy might actually think there is something in a sugar pill. But I agree that there is benefit to medical ritual, or that even having a doctor to talk to and listen to is beneficial for someone who had been suffering from something that a lot of people don’t consider a “real” disease. I hope there’s more follow up studies of this nature so we can see what slight changes might effect the results.

  2. Most people know of the Placebo effect – so they expect something called placebo to work, so I don’t see how the study removed the need to believe instead they re-enforced the belief people already had in placebos.

    Belief in the pills seemed to be re-enforced rather than removed by the test – of course that’s what they wanted to test so nothing wrong with that.

  3. Wow. I wonder what dose of placebo works best and if there are placebo-side effects.

    What appears to me to be a weakness in the study is, that patients suffering from a poorly understood condition like IBS were used.

    If I am not mistaken, IBS is sort of a rest category, when other causes have been ruled out. I.e. it is a proper ‘syndrome’, a collection of signs and symptoms appearing together, with, as yet, no apparent cause. As such, it is hard to say if patients diagnosed with IBS really have ‘the same problem’.

    The chronic element is not that there is discomfort all the time, but with some regularity over a year. A monitoring period of just three weeks seems pretty short to rule out any difference in relief between the groups arising simply by chance out of the ups and downs of IBS.

    There appears to be a psychosomatic element in IBS and patients suffering from IBS seem to have a relatively high rate of certain other diseases. Are the two groups similar with regard to psychological health and other diseases?

  4. I definitely agree with the comments pointing out that choosing patients with IBS creates certain conditions for the experiment that might not be replicated in other conditions. On the other hand, my sense is people seeking pills to make them feel faster before a race (a self-fulfilling prophecy if there ever was one) might share more in common with patients looking to recover from IBS than, say, trying to heal a broken leg.

  5. Well, my gut feeling (haha)is that it would work in athletes, provided they believe in the placebo effect.

    The litmus test would be to see whether an openly administered placebo works in people who don’t believe in the placebo effect. If it does, you’d have a lot of explaining to do. If not, you can pin the placebo effect down to belief or motivational factors.

  6. Elaborating on that:

    If the placebo effect is dependent on belief, a runner would have to entertain the mistaken belief that it is not, to gain any benefit from an openly administered placebo.

    Deception is saved.

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