The Middling Power of the Placebo Effect

The Middling Power of the Placebo Effect
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Alternative medicine practitioners love the placebo effect. To many of them, it is proof that the mind can heal the body through the power of positive thinking. While that is a tempting narrative, it is very much a tall tale. The placebo effect is not nearly as powerful as it's billed to be, nor can it be controlled with a simple thought.

Commonly witnessed in clinical trials, the placebo effect arises when sugar pills, sham surgeries, or any other fake treatments prompt improvements in patients' health. Such improvements result from an amalgamation of factors. Among these are genuine physiological effects, like the brain releasing "feel-good" hormones such as endorphins or dopamine. But the placebo effect also arises from problems that plague scientific studies. For example, subjects often report improvements in their symptoms out of a desire to please the researchers, or simply because they want to feel better. We humans are notoriously bad at gauging our actual health and wellbeing.

The placebo effect's standing is also inflated through a common misunderstanding about how it is measured. Franklin Miller and Donald Rosenstein, researchers based out of the National Institute of Mental Health, set the record straight back in 2006:

"Suppose that, in an 8-week trial, 50% of the patients respond to the investigational drug and 35% to placebo. The 35% response rate is typically described as the placebo effect deriving from receiving an inactive pill (the placebo) believed to represent a real drug."

But that is not the placebo effect! They continued:

"Just because 35% of patients in our hypothetical example were observed to have a reduction in depressive symptoms... it does not follow that the placebo administered in the trial caused this response rate. Patients who get better after receiving a placebo control may have improved as a result of the natural history of the disorder, natural healing, or the clinical attention they received by virtue of trial participation. In other words, they might have shown the same improvement without taking the placebo pill."

In fact, when researchers gathered 114 randomized trials conducted on forty medical conditions for a large meta-analysis, they found that patients given a placebo generally didn't fair much better than subjects given no treatment whatsoever. Only subjective measures of pain improved with placebos. 

"Outside the setting of clinical trials, there is no justification for the use of placebos," the researchers boldly and controversially concluded.

But is it that controversial? We will never be able to rely on a placebo to mend a broken bone or treat cancer. Patients may feel better, but that is not the same as actually being better.

"A great example of this is a study of sham acupuncture versus albuterol inhaler in patients with asthma." Science-Based Medicine's David Gorski wrote. "The results showed that, yes, patients did feel better. They did feel less short of breath. However, the “hard outcome” as measured by spirometry showed absolutely no effect on lung function."

While the placebo effect's power is decidedly overstated, we can still learn a lot from studying it. Again, Gorski:

"The science of placebos is a fascinating topic that might actually have some potential applications in medicine. These applications would at the very minimum include how to design better clinical trials whose results are not confounded by placebo factors. At the most, however, they would involve understanding how neurochemical functions can affect a patient’s perception of his or her symptoms and using that understanding to maximize the effects of science-based interventions."

(Image: Elaine and Arthur Shapiro)

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