In 1955, American physician Henry Beecher published observations he had made on U.S. soldiers during World War II in his book “The Powerful Placebo.” To relieve pain in these, he administered morphine. When he ran out, he replaced it with weak saline, with the effect that the “ineffective” substance relieved the pain of many soldiers. The word “placebo” comes from Latin and means “I will please.”
Preparations without therapeutic effect
Placebos are preparations that have no therapeutic effect. Instead of an active ingredient, placebo pills contain only fillers, such as lactose or starch. Today, placebos are often used in clinical trials designed to test the effectiveness of new drugs. In these so-called double-blind studies, one part of the test subjects receives the drug, another part the placebo. Surprisingly, subjects who have taken the “ineffective placebo” over the course of the study repeatedly show changes as a result of taking it. Both positive effects and side effects, so-called nocebo effects, can be observed in these.
Imagination, self-healing, miracles?
But what is the placebo effect all about? Are patients just imagining that the placebo will improve symptoms of their disease? Can the observed effect be blamed on the attention a patient receives under placebo treatment (the conversation with the doctor, examinations, etc.), or do self-healing powers of the body come into play as a result of the belief in the drug? The placebo effect preoccupies many scientists. Here are some approaches:
- Placebos show no effect at all. Effects, which one observes after placebo ingestion, find your explanation in the natural course of a disease. The improvement of the suffering coincides purely by chance with the taking.
- The placebo effect is explained by an interaction between the nervous system and the immune system.
- A recent study (Leuchter et al; Changes in brain function of depressed subjects during treatment with placebo; Am J Psychiatry 2002 Jan;159(1):122-9) demonstrates that there are changes in brain function with placebo use. Furthermore, it was shown that placebos could cause the release of endorphins.
Statistician Dr. John Bailar III explains the placebo effect as follows, “The belief in the existence of the placebo effect has become a kind of secular religion. And as with any religion, there is no evidence to dissuade a believer.”
