• The Mysteriously Powerful Placebo

    The placebo effect is one of the most powerful, and yet most mysterious, effects seen in medicine and health fields.  As the below video demonstrates extremely well, lots of research has focused on the effects of placebos and how it can differ across situations.

    Interestingly, it also turns out that placebos are, for some reason, getting stronger compared to two decades ago.

    Some products that have been on the market for decades, like Prozac, are faltering in more recent follow-up tests. In many cases, these are the compounds that, in the late ’90s, made Big Pharma more profitable than Big Oil. But if these same drugs were vetted now, the FDA might not approve some of them. Two comprehensive analyses of antidepressant trials have uncovered a dramatic increase in placebo response since the 1980s. One estimated that the so-called effect size (a measure of statistical significance) in placebo groups had nearly doubled over that time.

    And now, researchers have very cleverly shown that placebos can work even in people who know they are just placebos. Dr. Ted Kaptchuck and his colleagues published work in PLOS One that showed that telling patients they were being given placebos did not make the placebo effect disappear.

    Placebos without Deception: A Randomized Controlled Trial in Irritable Bowel Syndrome

    We found that patients given open-label placebo in the context of a supportive patient-practitioner relationship and a persuasive rationale had clinically meaningful symptom improvement that was significantly better than a no-treatment control group with matched patient-provider interaction.


    In summary, our study suggests that patients are willing to take open-label placebos and that such a treatment may have salubrious effects. Further research is warranted in IBS and perhaps other illnesses to confirm that placebo treatments can be beneficial when provided openly and to determine the best methods for administering such treatments.

    PlacebosVery interesting stuff, especially given that a vast majority of medical professionals have given or prescribed a placebo at some point in their careers. In some specialty areas, it appears to even be fairly normative to do so on a regular basis.

    Although there are numerous problems with the study (including lack of really solid outcome measures or behavioral logs rather than clinician- and self-report; the fact that they were told the placebos “have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes,” which says they were told that it would work; and finally that the placebo itself – in terms of what it is composed of – may actually cause some changes in the gut environment), I think it is a very interesting start and should certainly be followed up on.

    One of the assignments I give the students in my Science vs Pseudoscience course after we discuss alternative medicine is to answer the following question. I’d be interested to hear your responses in the comments.

    If these (the impact on health of alt-med) are just placebo effects, and some people benefit from them, what is your opinion regarding people using complementary and alternative medicine (CAM) if there is no health risk?

    Category: HealthMental HealthScience


    Article by: Caleb Lack

    Caleb Lack is the author of "Great Plains Skeptic" on SIN, as well as a clinical psychologist, professor, and researcher. His website contains many more exciting details, visit it at www.caleblack.com

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    • Every time I try to think about this question, my ideas in up in a giant ten-dimensional pretzel!

      One fundamental point that I try to keep in mind is, outside of medical products, how much known psychological manipulation our society already endorses. Stores pumping in music and scents that are proven to make people buy more. Perfumes that trick others’ sense of smell to improve perception of the wearer. Beer that’s sold, not on how tasty or refreshing or high in alcohol it is, but by pairing it with hot women and awesome parties to create subconscious associations. Advertisers and journalists and lobbyists citing (true) statistics in particular formats, designed to exploit all the ways in which our automatic cognitive systems are terrible at understanding numbers. Products for $199.99. Photoshop, Photoshop, and also Photoshop.

      Compared with some of these examples, CAM products seem to have an equal or better claim to increase aggregate well-being, at least in the short term. So if one’s going to make a case for “honesty” or against “manipulation”, can we justify aiming it narrowly at CAM versus broadly?

      • One point I make when I teach critical thinking skills in my various courses is that they should be applied to ALL aspects of life. Not just the supernatural, or CAM, or any other narrowly defined area – to LIFE as a whole.

    • qbsmd

      There’s a well known bias toward publishing studies that show a drug to be effective over studies that show a drug to not be effective. This would create a bias toward overestimating the effect of the drug studies as well as underestimating the placebo effect. There’s a also a bias in scientific publications, written about by Richard Feynman, for results published over time to slowly drift from the originally accepted results toward the true results rather than being scattered with a mean around the true result. This is because someone who gets a result that is wildly different from expectations goes back and looks for problems. They find problems and fix them until their result is close to the expected value and then conclude they’ve fixed everything. Someone who gets a result close to the expected value the first time doesn’t go to the same effort of finding errors.

      Given these two well known biases, it’s not surprising that the placebo effect appears to have been getting more powerful. I predict that lots of drugs will be discovered to be no better than placebos over time.

      SSRIs have been suspect for a while as I understand it; no one understands why they work or why drugs that should have similar effects behave differently in different people (the standard practice is to give people different SSRIs at random until finding one that “works”). I thought originally they weren’t required to be tested against placebos, but only against the standard of care at the time they were released (usually other SSRIs), and studies comparing them to placebos always showed them to be limited.

      • Great points on publication biases.

        re: SSRIs – The most recent, larger meta-analyses have all found very little benefit for SSRIs above and beyond a placebo effect, especially for mild to moderate depressive/anxious symptoms, and maybe not much of an effect for even severe symptoms (see http://www.ncbi.nlm.nih.gov/pubmed/20051569 or http://www.ncbi.nlm.nih.gov/pubmed/18303940).

        • qbsmd

          Yeah, I’ve heard about those studies; I remember getting the impression that SSRIs have side effects that are severe enough to make good placebos yet mild enough to be widely prescribed.

          Do you have information of the effectiveness of other psychiatric or psychological treatments? My impression is that anti-psychotics and anti-hallucinagens work well, but the majority of people seeing psychologists would get the same benefit from a psychic, priest, or homeopathic remedy. But I haven’t seen a lot of criticism of psychology or psychiatric drugs from skeptics.

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