Spies, magicians, and Enid Blyton: how they can help improve clinical trials.

Abstract

Some of the most important methods for preventing bias in modern clinical trials have a peculiar history, Masked assessment with placebo control seems to have appeared first during tests led by Benjamin Franklin in 1784 to investigate unorthodox claims of healing by 'animal magnetism' or 'mesmerism'. People were blindfolded and told that they were or were not receiving magnetism, when the reverse was true, and were given sham treatments of 'mesmerised water'. 1 Similar methods were used to test claims of 'higher' mesmeric phenomena such as thought-reading and precognition. 2 Two-hundred years later, the same methodology is still used to assess controversial claims in parapsychology, a subdiscipline of experimental psychology, that uses controlled laboratory techniques to examine claims of psychic abilities. Recent problems noted with the conduct of clinical trials suggest that although the two fields have diverged, parapsychology might now have something to offer in the design of orthodox medical research.