Yesterday, the Times reported the results of an intriguing new study, just published in the Journal of the American Medical Association (subscription required). The focus of the story: the placebo effect.
The existence of a placebo effect is well known, and the best work on this topic comes from Anup Malani, another economist (and a good friend) who currently teaches at the University of Chicago Law School. It is now well established that giving a patient a sugar pill (while telling them that it may be medication) can actually have therapeutic effects.
But this new study – by Dan Ariely and coauthors – shows that the placebo effect is itself subject to experimental manipulation. Their experiment is incredibly clever, and very convincing.
The subjects were given an initial series of electric shocks and asked to rate the pain they felt after each shock. The subjects were then allowed to take a placebo pill that they were told was similar to codeine. In fact, the pill had no direct medical benefit at all. While half of the patients were told that their (false) treatment cost $2.50 per pill, the other half were told that their pill had been discounted to $0.10 per pill. They were then given a second series of electric shocks, and once again, asked about how much it hurt.
While 85 percent of the patients taking the $2.50 pill reported that the second set of shocks were less painful, only 61 percent of those taking the (identical!) $0.10 pill reported the shocks to be less painful. So the more expensive the pill, it seems, the larger its perceived effect – even when the pill actually has no medical effect!
And yes, this study was co-authored by the same Dan Ariely who wrote the recently-published popular behavioral economics book, Predictably Irrational.
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I work in sales and have seen this occur with the “it’s too good to be true” response. When we charged for our service up front, we often heard that it was too expensive. When we started offering a trial month, we now often hear that “it’s too good to be true.” That’s the same thing going on with the placebo. I’m sure the people that heard they were getting the discounted drug were more likely to feel there was no way a drug so cheap could work.
For all the apparent “power” of the placebo effect … and its power is so strongly accepted now, that I’ve seen mass-media stories about whether or not doctors should prescribe plabecos … we need to remember something.
In current practice, the “placebo effect” is merely a baseline for determining efficacy. Accepted and approved treatments are those which exceed “placebo effect”; i.e. more people are helped by them, than by placebo. The determination that there are treatments better than placebo, by definition shows that, statistically speaking, the “placebo effect” is actually LESS POWERFUL than these known alternatives.
David, there was a test similar to what you were speaking about that I read about a while ago with spirits. Rather than the specific price, one bottle looked “more expensive” than the other and people associated that with better taste. I think it was in “Blink”, by Malcolm Gladwell.
So Canadian drugs might not work as well as the identical but more expensive American drugs?
What if sugar pills really are the miracle drug?
On a slightly different note: I wonder if there have been any studies on the effect of real medication on patients who think they are taking a placebo?
* would the the real medication have less of an effect than normal? (I’m assuming probably, but by how much?)
* also what about affect on the frequency of side-effects?
Then stop telling me “you get what you pay for”!
It seems one could easily extend this experiment to test generics vs. brand-name drugs, which are also chemically identical products marketed to the consumer differently. BigPharma has been arguing forever that generics, are not, in fact, the same as their brand-name versions – and maybe they’re right (but for the wrong reason).
One wonders if the same results would be obtained in a less consumer-oriented, brand-driven culture, or if this effect is peculiar to patients in the U.S..