Émile Coué, a French pharmacist, working as an apothecary at Troyes between 1882 and 1910, also advocated the effectiveness of the "Placebo Effect". He became known for reassuring his clients by praising each remedy's efficiency and leaving a small positive notice with each given medication. His book Self-Mastery Through Conscious Autosuggestion was published in England (1920) and in the United States (1922).
Placebos remained widespread in medicine until the 20th century, and they were sometimes endorsed as necessary deceptions.[11] In 1903, Richard Cabot said that he was brought up to use placebos,[11] but he ultimately concluded by saying that "I have not yet found any case in which a lie does not do more harm than good".[20]
In modern times, T. C. Graves first defined the "placebo effect" in a published paper in The Lancet in 1920.[185] He spoke of "the placebo effects of drugs" being manifested in those cases where "a real psychotherapeutic effect appears to have been produced".[186] In 1961 Henry K. Beecher concluded[187] that surgeons he categorized as enthusiasts relieved their patients' chest pain and heart problems more than skeptic surgeons.[20] Beginning in the 1960s, the placebo effect became widely recognized and placebo-controlled trials became the norm in the approval of new medications.[188]
Placebo-controlled studies[edit]
Main article: Placebo-controlled studies
The placebo effect makes it more difficult to evaluate new treatments. Clinical trials control for this effect by including a group of subjects that receives a sham treatment. The subjects in such trials are blinded as to whether they receive the treatment or a placebo. If a person is given a placebo under one name, and they respond, they will respond in the same way on a later occasion to that placebo under that name but not if under another.[189] Clinical trials are often double-blinded so that the researchers also do not know which test subjects are receiving the active or placebo treatment. The placebo effect in such clinical trials is weaker than in normal therapy since the subjects are not sure whether the treatment they are receiving is active.[88]
Knowingly giving a person a placebo when there is an effective treatment available is a bioethically complex issue. While placebo-controlled trials might provide information about the effectiveness of a treatment, it denies some patients what could be the best available (if unproven) treatment. Informed consent is usually required for a study to be considered ethical, including the disclosure that some test subjects will receive placebo treatments.
The ethics of placebo-controlled studies have been debated in the revision process of the Declaration of Helsinki.[190] Of particular concern has been the difference between trials comparing inert placebos with experimental treatments, versus comparing the best available treatment with an experimental treatment; and differences between trials in the sponsor's developed countries versus the trial's targeted developing countries.[191]