Effect Measure

“I will please” (placebo)

A study just published in the British Medical Journal (full disclosure: I haven’t read it, only seen wire service reports of it, but I have absolute confidence it is true — or, more accurately, I’d say it accords 100% with my prior beliefs so I’d have no reason to question it), says that US doctors routinely prescribe drugs purely for their placebo effect, believing they have no other substantive efficacy:

Almost half of the rheumatologists and internists surveyed said they prescribed pills whose benefits derive from “positive patient expectations” two to three times a month, Jon Tilburt from the National Institutes of Health in the U.S. said in a study published today in the British Medical Journal.


Tilburt and colleagues from the NIH and scientists from Harvard Medical School and the University of Chicago surveyed 1,200 internal medicine physicians and rheumatologists, doctors who commonly treat patients with chronic conditions that are difficult to manage.

Of the 57 percent of physicians who responded to the confidential survey, 61 percent said they believe it is ethically acceptable or even obligatory to recommend or prescribe placebo treatments.

Forty-one percent of the doctors prescribed over-the-counter painkillers and 38 percent prescribed vitamins. Thirteen percent used antibiotics and sedatives.

Only 2 percent of the doctors used actual sugar pills and 3 percent used salt water-based treatments. (Chantal Britt, Bloomberg)

There are some ethical tangles here regarding deliberate deception. I’ll leave that to the bioethicists. What has always interested me about placebos is that in study after study they work. It’s not just beneficial effects, either. Placebo drugs have been shown to have a higher rate of headache, nausea and dizziness. If they had absolutely no effect at all then it wouldn’t be necessary to have placebo controlled drug trials. We could just give the drug and compare it to no treatment at all.

In my father’s time (60 years ago) a large injection with a big syringe of red vitamin B12 was a common placebo treatment. Vitamin B12 is a real vitamin, good for you if you don’t have enough of it. Beyond that it is just a syringe full of red liquid. And indeed the BMJ authors observe that doctors engaged in this practice still prefer “active placebo treatments” rather than inert agents. One reason is that you can’t write a prescription for a sugar pill and there is no official and marketed placebo agent.

One explanation may be that placebos work best when both the patient and the doctor believe they work (even if for different reasons). I suspect that an awful lot of things we doctors do for patients is really placebo medicine. It’s just both doctor and patient (falsely) believe they are effective. But writing prescriptions for things that have biological activity like antibiotics or sedatives is problematic if there is no expectation they will have any benefit for what ails the patient. And let’s face it. Lots of doctors write prescriptions to please the patient, or more accurately, to keep the patient’s business.

Some people are probably helped. But an awful lot more aren’t. The chief beneficiaries are the drug and insurance companies.


  1. #1 Jonathon Singleton
    October 25, 2008

    Thank you Revere, this information is fascinating for many reasons. Bit of a concern though, doctors prescribing and charging patients for biologically active sedatives and/or antibiotics without proper need — I wonder if those drugs which put you to sleep, antidepressants, are used also!?!

  2. #2 K
    October 25, 2008

    Not everyone has a positive response to a placebo. Are there any studies about what kinds of people respond? I would guess that those who are easy to hypnotize are more likely to have a positive effect from a placebo. Any studies on that?

    I have always thought it would be a good idea to harness the placebo effect for treatment as there is less likelihood of side effects from placebo treatment. If we could harness our own bodies ability to heal itself without using a placebo wouldn’t that be great…oh not for the drug companies….

    so it goes

  3. #3 SaddleTramp
    October 25, 2008

    I’ve long considered prayer (by both the patient and others praying for the patient – usually with the patient’s knowledge) to be a very effective placebo. It might not actually do anything to help cure the illness or injury, but for many folks, it does make them feel better.


  4. #4 Orac
    October 26, 2008

    It’s not entirely true that placebos “work.” They only “work” for some conditions. For example, no one has ever been able to show me a study where a placebo shrank a tumor or prolonged the lives of cancer patients.

  5. #5 revere
    October 26, 2008

    orac: Antibiotics “don’t work” either for some conditions. I think the meaning was clear from context.

  6. #6 daedalus2u
    October 26, 2008

    My conceptualization of the placebo effect is that it is the neurogenic invocation of the opposite of the “fight or flight” state.


    In the “fight or flight” state, metabolic resources are mobilized and held ready for use at a moments notice. Because ATP cannot be stored, and it takes some time to rev up all the systems to produce it at high rate, under conditions of “fight or flight”, potential ATP production rate is maximized with the mitochondrial potential being dissipated as heat.

    In addition to maximizing ATP production, “fight or flight” also minimizes ATP consumption by turning off systems with a lower priority. When one is running from a bear, healing damage is a very low priority because if the bear catches you, you are dead. It is better to divert the ATP that would be used for healing into running from the bear.

    Ischemic preconditioning is a version of this, where brief periods of ischemia invoke a physiological state where ATP consumption is reduced and so the tissue compartment can survive ischemic insults that would be fatal without the ischemic preconditioning.

    This is why “stress” makes just about every condition worse; ATP is being diverted away from healing so as to better cope with the “stress” (which in evolutionary times was usually running from a predator). Better to survive and heal later than keep healing and be caught.

    It might be possible to shrink some tumors with the placebo effect, but I think you would have to pharmacologically invoke it (which makes it not really a placebo). I think you might be able to with something like a LPS induced state of septic shock. The very high NO levels of sepsis do raise ATP levels in all cells which activates autophagy to a high degree. In cells that can sustain this very high ATP level through glycolysis, the mitochondria stay off. If the mitochondria turn on, then the high NO levels can kill them, and the cell that they are in and the tissue compartment they are in. That is the mechanism for multiple organ failure in septic shock. I suspect that healthy organs and healthy tissue in organs will be more resistant to death by this mechanism than will tumor cells.

  7. #7 g336
    October 27, 2008

    Confidence is an emotion. Emotions are contagious. Emotional states are chemical states in the brain. The brain is wired to the rest of the body. And so we will probably come to find that various neuropeptides, neurohormones, and the other compounds produced by or released into the body as an effect thereof, have broad-spectrum effects on other bodily systems. This also explains some of the benefits of prayer on health: your loved one is at your bedside, you pray together, and so it goes.

    As for hypnosis, virtually everyone is hypnotizable given the right induction procedure for their cognitive, emotional, and perceptual style (the competent psychologist or therapist will have ascertained this before using hypnosis). In fact, if given half a chance, most people will go very happily into various kinds of trance states. Who among us doesn’t like to daydream? All the better if it can be a productive exercise in problem-solving.

    Antibiotics are dangerous placebos because, as we all know, they produce selectoin pressure for resistant bugs. But aside from that, I see no reason not to give someone, for example, a sleeping pill for a cold.

    Write the prescription for one sleeping pill at about half the strength you would expect to use for that person’s body weight. Tell the patient to take it two hours before their normal bedtime and climb into bed shortly thereafter. We are a chronically sleep-deprived culture, and adequate sleep, after all, gives the body’s defense mechanisms a better chance to fight a bug. Now they have the doctor’s permission to sleep, and a mild dose to help nudge them along, and eight hours later they wake up feeling at least a little better than the day before: good for confidence, thus good for their health.

    Gargling with warm salt water, so far as I can tell from my experience, seems to be useful. I just killed off a sore throat that way last week, that was on its way to becoming a cold; I didn’t get the cold. So if that’s a placebo, it’s a very nice one because it has zero harmful side effects, and I’ll keep using it consciously.

    In fact something tells me that if someone knows they are getting a placebo, but they take it in the right frame of mind, it will also work. This should become the subject of controlled experiments.

    All in all, I’m in favor of conscientious use of placebos, preferably with informed consent. The fact that they work should be cause for great joy: rejoice, for the human body is good at healing itself, and nature has done a good job with us!

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