The Incredible, (Sometimes) Edible Placebo

Robin Hanson proposes that placebos work because the person who administers the placebo shows care for the patient.

Can placebos work even if a patient knows he is receiving a placebo? So claims a person who left a comment on Hanson's blog post:

Interestingly, you can also invoke the placebo effect out of seemingly nothing, by truly telling the people that they are receiving placebos, *but* telling them at the same time that placebos work even if you know they are placebos. The trick is that this still builds on the core of medicine's reputation, so the patient believes this claim, so he has the expectation and now the placebo effect kicks in. This effect cannot be attributed to the pill's reputation, it's due to the doc saying that science shows that the placebo will work. Which it really will, in a self-fulfilling prophecy way.

There are lots of fascinating scientific and philosophical questions relating to placebos. It seems like research on placebos and interest in the therapeutic aspects of placebos has been increasing in the last 10 or so years. Here are some links which summarize the findings thus far:

1. Steven Novella, "The Poor, Misunderstood Placebo," Skeptical Inquirer 34.6 (November/December 2010).

2. "Putting the Placebo Effect to Work," Harvard Health Publications (April 1, 2012).

3. Aaron E. Carroll, "The Placebo Effect Doesn't Just Apply to Pills," The Upshot (October 6, 2014).


And here are a couple of interesting studies on the placebo effect:

1. Mayberg et al., "The Functional Neuroanatomy of the Placebo Effect," The American Journal of Psychiatry 150 (2002): 728-737.

2. Meissner et al., "The Placebo Effect: Advances from Different Methodological Approaches," The Journal of Neuroscience 31 (9 November 2011): 16117-16124.