The placebo effect: Now with 100% fewer lies


If you read Steve Silberman's excellent Wired story on placebos last year then you know that fake medicine can have some very real effects. Scientists are only beginning to ask the important questions here—why placebos seem to be able to alleviate certain medical problems, why they don't have much impact on others, and what all of this tells us about the human body.

But, looming behind those questions is a nagging, clawing beast. Even if placebos can be medicine on a technical level, could we ever ethically use them? Most of us agree that it would be wrong for doctors to lie to patients, even if it might help the patients feel better. And most of us assume that lies are part of how placebos work.

But that may not be true.

A small study, recently published the journal PLoS One, looked at what might happen if the irritable bowel syndrome patients who received a placebo knew they were taking nothing more than sugar pill. Amazingly, the placebo group improved. In fact, they improved as much as the people taking the real drug. These results aren't comprehensive. As Silberman explains in a nuanced and fascinating blog post, this is the first word on ethical placebos—not the last. But the questions it raises are important ones. The research that will come out of this line of inquiry could change the way our children and grandchildren think about medicine and health. And it opens whole barrels of worms ...

Its modest sample size and brief duration leave plenty of room for followup research. (What if "ethical" placebos wear off more quickly than deceptive ones? Does the fact that most of the volunteers in this study were women have any bearing on the outcome? Were any of the volunteers skeptical that the placebo effect is real, and did that affect their response to treatment?)

Before some eager editor out there composes a tweet-baiting headline suggesting that placebos are about to drive Big Pharma out of business, he or she should appreciate the fact that the advent of AMA-approved placebo treatments would open numerous cans of fascinatingly tangled worms. For example, since the precise nature of placebo effects is shaped largely by patients' expectations, would the advertised potency and side effects of theoretical products like Placebex and Therastim be subject to change by Internet rumors, requiring perpetual updating?

Read More: Meet the Ethical Placebo by Steve Silberman

Image: Some rights reserved by Mykl Roventine


    1. If you read Silberman’s blog, you’ll see that it was explained to them, in detail, as part of the methodology. So, even if they went in not knowing what placebo meant, they knew before they started taking it.

  1. Hmmm, they must have known about the psychological effect of placebos, and expected to experience it.

    It’s a placebo placebo!

  2. Looking at the summary (and also at the article linked on /.), the control group was given *no treatment* rather than a regular medicine.

    I find that the study muddies the waters a bit. My understanding of the placebo effect is that it’s dependent on the fact that there is an intervention, a ritual, like the doctor handing out pills. So by handing out a placebo, the ritual is performed, and the placebo effect can take place.

    In my opinion, a better study would dispense medication by vending machine (no human interaction), and randomly either provide pills labelled “placebo” with an explanation of the word, or pills labelled “medicine”, or blank pills. If there’s a difference between the groups, it’d be dependent on their understanding of what they’re taking, not so much the ritual involved in administering the pill.

  3. I wonder about the long term affects. Many medicines lose effectiveness as one gets used to them. Would you see a similar effect curve with placebos?

    Would increasing the dosage help?

  4. I wonder if there’s ever been a study done comparing the effectiveness of a placebo vs. prayer. I bet you the placebo works more of the time.

  5. Interesting commentary on this from Orac over at science blogs ( If I’m understanding his point correctly, the main problem with this study (and there are many) is that the subjects were essentially deceived into thinking that placebos are already known to have a specific bio-mechanical effect, which sets the “placebo” group up to have effects larger than the placebo itself.

    I.e. in a normal study, the control group would be experiencing the effects of the placebo alone because everyone in the study has the same expectation of efficacy. In this case, the control group had zero expectation of efficacy because they knew they weren’t receiving treatment. So the way I see it, all this study did was test the effectiveness of a degree of belief, not the effectiveness of an actual placebo pill.

  6. I’d go see that band!! (assuming, of course, my gastrointestinal issues are kept in check by genuflection)

  7. Did they ask the participants if they thought the Doctors where lying to them when they were told they were being given a placebo?

    The Placebo effect is that the patient believes they are getting a real drug. So if the patient thinks the Doctor is lying to them about getting a placebo, and instead believe they are actually getting a real drug, then the Placebo Effect still holds true.

    After all, the whole study is about the effectiveness of lying.

  8. I think it’s indeed a psychological issue, but not the one you’d expect: the mere fact that ill people feel they are being monitored by medical staff, being taken care of, will ease the psycological stress of being ill. Which in turn facilitates the physical healing. Or even completely removes the very cause of the illness: stress and anxiety. Just a thought….

  9. a similar study was spoke about in ben goldacre’s ‘bad science’. this isn’t the ‘first word on ethical placebo’ such as it were.

  10. Placebo’s “work” for several reasons.
    The simplest is that in any group of people with a particular ailment, SOME of them will always get better no matter what. Pill, no pill, etc..
    Then there is the regression to the mean affect. I gots a headache that is absolutely killing me, worst I ever had. Take a pill, half hour it’s gone. Well, chances are it was on it’s way out anyhow, I just took a pill when the headache pain had peaked. This happens to dupes that take homeopath stuff for their problems.

    1. Perhaps you haven’t heard about a thing called statistical significance, but doctors/statisticians/researchers have.

  11. It’s also important to note that the placebo effect is way more complicated than is commonly portrayed. It’s not simply a case of the mind healing the body.

    Patients may not feel better, but may unconsciously report improvements or downplay problems to please the researchers interviewing them. Researchers may let their biases shine though and see an improvement somewhere it isn’t (thus making a placebo effect possible even in animal studies). I don’t know anything about the tools being used to collect data, but if they rely upon subjective or subject-reported information that immediately casts a lot of doubt on the idea that these people are seeing meaningful improvement.

  12. Treating irritable bowel syndrome with ethical placebos really does open another whole barrels of worms, since medical researchers are also now experimenting with… wait for it… worms.

  13. Has anyone done research into whether or not a small daily dose of sugar in pill form can be beneficial for some conditions? Maybe it’s not mental at all…

  14. The tablet offered contained gelatin and a processed form of cellulose (avicel), but importantly were blue and maroon in colour. I’ve read that coloured tablets work better as placebos than white tablets; that capsules are more effective than tablets; that injections are more effective than oral medication; that coloured injections are more effective than clear injections; and that red injections are more effective than blue injections. As a medic I know the power of instilling confidence in the treatment to the patient – and this in turn leads to the temptation of over-selling the effectiveness of a treatment to try and invoke this placebo effect. When statistics intervenes and the true response rate bears out, this temptation is tempered.

  15. “Amazingly, the placebo group improved. In fact, they improved as much as the people taking the real drug.”

    Just want to point out that the trial was actually not placebo vs. drug, it was “we’re giving you a sugar pill that will have no pharmacological effect but may actually help you anyway” vs. “we’re not giving you anything other than the same doctor visits the people in the other arm get.”

    That’s what makes this study novel and kind of fascinating. All previous comparisons have been placebo vs. actual drug (in which case, the drug is shown to not be beneficial) or blinded placebo studies where people didn’t know they weren’t getting a potentially bioactive drug. Here, nobody’s getting anything, and everybody knows it. And STILL the placebo worked. That’s the awesome part.

  16. It all depends on how you define irritable bowel syndrome, does it have a physiological certified cause? If not, and its “just” a psychosomatic manifestation neither the drug nor the placebo should be used.

  17. these people had Irritable Bowel Syndrome – that means there is already something wonky (that’s the clinical term ya know)with them – which makes their bodies ‘think’ there is something wrong with them when there is actually nothing wrong. Their bodies just act like there is something wrong.

    my question is – does this really prove the coolness of placebo or the power of suggestion upon IBS.

  18. jasoncardillo, sorry, but Orac’s post is much less authoritatively withering than he seems to believe. He disses PloS versus NJEM, he disses the trial for not being blinded — hard to pull off when you’re specifically running an open-label trial! — and he reveals his bias here:

    “In other words, not only did Kaptchuk et al deceive their subjects to trigger placebo effects, whether they realize or will admit that that’s what they did or not, but they might very well have specifically attracted patients more prone to believing that the power of ‘mind-body’ interactions. Yes, patients were informed that they were receiving a placebo, but that knowledge was tainted by what the investigators told them about what the placebo pills could do. After all, investigators told subjects in the placebo group that science says that the placebo pills they would take were capable of activating some sort of woo-ful mind-body’ healing process.”

    Since this was a test of _how beliefs elicit placebo effects_, the word “tainted” is clearly misleading. Orac’s critique of the demographics of this study seems valid, but his use of terms like “woo-ful,” and his harping on the phrase “mind-body,” say more about what Orac felt certain of before he read the study than they do about the study.

  19. What about giving half the group the placebo, and half the group the drug and telling the whole group they are all taking a placebo and that is not supposed to help?

    1. roboton, this would likely be considered unethical and wouldn’t get past the ethics committee. You have to be open with people about the nature of the study, even if they don’t get to know whether they are taking the active drug or a placebo.

      I’m currently a research assistant for a randomised double-blind placebo-controlled trial for high dose multi-vitamin and mineral supplements for the treatment of adult ADHD. It has been a very interesting experience, and if the results turn out the way the principle investigator expects, your may hear about it in about a year’s time.

  20. I wonder, could anyone make a drug that would actually increase the effectiveness of the placebo effect? I also wonder how you would test that.

    I also wonder if the placebo effect is most dominantly effective on maladies that are induced by the nocebo effect; the mind causing damage to the body.

  21. … and then there’s the reverse placebo effect. If you give placebos to people, tell them to list the side effects of the “experimental medication” they’re taking, they will list headache, nausea, tinnitus, drowsiness….

  22. If we’re talking about whether or not it’s ethical to give a patient a placebo while telling them it’s a placebo, why not shift the responsibility from the doctor? If the patient knows what it is and can get it without a medical license, can’t they handle it themselves?

  23. That’s not how the placebo effect works. It’s not about what’s in the pill; it’s about the social context, as Irving Kirsch makes clear in my interview with him behind the link.

  24. It seems to me that the placebo effect works the same way faith healing or plenty of ancient techniques work- belief is as strong a factor as anything else we’ve been able to come up with. Just because we haven´t figured out how the science works doesn´t mean it´s bullshit; there’s enough evidence to show that SOMEthing is up, that the mind definitely affects the external world in ways we can observe but don’t understand.

    It is surprising that people can be aware of the placebo and still feel the effects. However, that has a lot to do with the people. I´m sure we all know people that do things that are seemingly irrational and yet it works for them, despite them admitting outright that they know it doesn´t make sense. Yet me, for example, as much as I believe in the power of belief, because I’m “aware of the strings” so to speak, it never works. I´m too much of a skeptic… yet the things that I do genuinely believe, even when I have no way to prove them, are 100% dependable.

    In short, the power of the mind is something way greater than we really understand, and I wonder if, in this case, ignorance is bliss. Perhaps, the more we know, the less it will work…?

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