Placebo is not what you think

The New York Times covers an interesting development in the world of consumer medicine – a company selling placebos to consumers that they can use to ease their children’s ills.

For doctors, the use of placebos to treat medical conditions is explicitly banned by most medical associations but their use is widely debated.

Thousands of clinical trials have shown us that placebo is one of the most effective and safest of medicines (although it is not entirely without side-effects).

However, it is also one of the most misunderstood of treatments.

An article in this month’s Journal of the Royal Society of Medicine (which has been debating placebo over the past year or two) dispels some of the myths.

The placebo effect is usually equated with the average response of patients receiving placebo controls in randomized trials. However, it’s not quite that simple.

For example, not every improvement that happens after someone is given a placebo treatment is the ‘placebo effect’ (some symptoms will just get better by themselves) and not every improvement after medication is the active effect of the drug, some of that will be ‘placebo effect’ too.

Placebos are not ‘ineffective’. In fact, when three condition trials are run (no treatment vs placebo vs medical treatment), placebo consistently out performs ‘no treatment’ and of course, not uncommonly, the medical treatment condition as well.

Placebos are not a ‘non-specific’ treatment. A study on people who take the dopamine-boosting drug L-DOPA for Parkinson’s disease but who took a placebo L-DOPA pill, showed almost identical brain changes, as if they’d taken the real thing.

Furthermore, studies done in the 1970s showed that when heroin users inject water (sometimes done deliberately to alleviate cravings when drugs are in short supply), they can experience drug-like euphoria and have been observed to show opiate-like physiological signs such as pupil constriction.

This last point also demonstrates that placebo is not solely about expectancy, belief or ‘being fooled’, as the heroin users knew they were injecting themselves with water. Conditioned responses play a role.

This can also be seen from the fact that these specific effects of placebo tend to fade after a while, as the conditioning becomes extinguished.

The fact that placebo can be a relatively safe, effective, and sometimes selective treatment has led some to argue that doctors should be able to use it officially (although, of course, many use it unofficially).

Law professor Adam Kolber (who you may know from the excellent Neuroethics and Law blog) wrote a fascinating paper last year that reviewed the research and argued that in limited circumstances, placebos could be ethically used.

The article is available online and I really recommend reading the ‘Avoiding Deception’ section if nothing else – for series of recommendations on how placebo could be used without straight up deception.

Link to NYT on buy-your-own placebos for kids.
Link to JRSM article on placebo. Full text here (thanks Ines!).
Link to Adam Kolber’s article (scroll down for free full text download).

3 thoughts on “Placebo is not what you think”

  1. Thanks for the information on placebos. Whoever thought up selling placebos to kids? I wonder if people will even bother to buy it.
    We recently wrote an article on placebos at Brain Blogger. A recent survey of more than 200 doctors that practice in academic medical centers, showed that 45% of them had given placebos to patients while providing clinical care. Is this right though? Is giving a pateint a placebo a form of betrayal?
    We would like to read your comments on our article. Thank you.

  2. I think promoting Placebo treatment is slightly silly:
    It means that you acknowledge psychology’s role but instead of teaching the patient to control their own psychology (via self brainwashing-hypnosis courses for example), you treat them like sheep and try to do their job for them.
    It’s not just deceving the patient, the doctors are also deceiving themselves by convincing themselves that they did the best for the patient while they could have done better by informing the patient about what THEY can do.
    I still support the prescription of placebos though…better than prescribing something harmful. I just think that it’s not the perfect solution.

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