In 1997, researchers in Germany revisited “The Powerful Placebo” and were stunned by what they found. They reviewed the details of the original 15 trials cited by Beecher in evidence of the placebo effect.

None of them supported his thesis.

Yes, patients in the placebo group often got better. But some also got worse (a fact that Beecher neglected to include in his statistics). A natural fluctuation of disease is common without any treatment, so improvement in a few patients provides no evidence of a special “placebo effect”. Other causes of improvement, such as observer bias, switching of treatments in the middle of the experiment, or a desire of the patient to please the experimenters, were lumped together into a single category, the placebo.

Worse, Beecher was found guilty of repeatedly “misquoting” research results.

As an extreme example of misquotation, the authors describe “Beecher’s claim that in a study of antitussive [anti-coughing] agents there was a placebo effect in 36% of 22 patients and in 43% of another 22 patients. However… under none of the placebo administrations could any significant change be demonstrated… Thus, Beecher’s quotation was wrong (which is amazing, as Beecher himself had been one of the authors of the original publication).” [emphasis added.]

Surely Beecher knew of the concept of spontaneous remission of disease. Even more surely he had been familiar with the details of his own papers. He was as pre-eminent a scientist in the 1950s and 1960s as Dr. Rush had been in the 1790s. Yet the 1997 review found that he had misquoted results in 10 out of the 15 papers studied, and clearly stretched his interpretations to make data fit the concept of a “powerful placebo” in the others.

Could Beecher have really made such basic mistakes? Or did he purposefully bias his own paper to demonstrate a “powerful placebo”, knowing that this would attract doctors to support his true goal: the establishment of controlled trials as central to medicine?

Whatever the cause, the paper was one of the most influential in modern medicine. Google Scholar tracks almost 2000 citations. Even grade school children have heard of the “placebo effect”.

And we hold to this belief to this day, even though subsequent studies have confirmed that the placebo effect does not actually exist.

In 2001, researchers published a paper comparing trials which had both a placebo and a “no-treatment” control, and found there were no differences between the two. Taking a placebo did not change patient outcomes.

The researchers repeated these reviews in 2004 and 2010 with the same results. Placebos do not make patients better.

At best, the reviewers detected a placebo effect only for self-reported results such as pain, and only when there is a continuous, graded outcome (such as a scale of 1–10) rather than a binary outcome (pain or “no pain”). And even in these cases, there is a great chance that patients are claiming mild improvements in order to meet the perceived wishes of the experimenter, not because they actually felt better.

The placebo effect can only be seen when patients have an opportunity to fudge the results.