A placebo is a substance or treatment designed to have no real therapeutic quality. The placebo effect is patient’s perceived belief in treatment’s effectiveness. It has been studied since 18th century, and confirmed by influential 1955 research study titled The Powerful Placebo. Patients can perceive therapeutic outcome of treatment even when they are treated with sugar pills that cannot possibly have real medicinal value.
Phenomenon of placebo effect
The phenomenon of placebo effect has been widely used in blinded experiments – research studies in which participants don’t know whether they are issued real medicine, or just sugar pills. Human mind is susceptible to various psychological phenomenons like observer’s effect on the participants, observer bias, confirmation bias. Best research studies use double-blind experiments, where the information about placebo is withheld not only from participants, but also from the researchers.
Expensive placebo is better
Dr Dan Ariely, a behavioral economist at Duke University published findings of his provocative 2008 study titled Commercial features of placebo and therapeutic efficacy. He recruited 82 paid volunteers in Boston, Massachusetts. He informed the participants of the experiment, that they will receive electric shocks to their wrist, and afterwards will be given new painkiller pills. Half of the volunteers were informed that they are receiving a painkiller priced $2.50 per pill, and the other half received a discount drug priced $0.10 per pill.
All of participants actually received placebo pills. Surprisingly (or maybe not), 85% of volunteers experienced pain reduction after taking the costly pill, and only 61% reported feeling pain relief after receiving the discount pill.
Dan Ariely received Ig Nobel award in Medicine for his paper. He is a big fan of the award, and accepted it in person. In his own words: Ig Nobel — a dream come true.
Red pill or blue capsule?
Scientists are fascinated by placebo effect, and numerous studies and experiments were devoted to placebos. As a result, research studies found that placebo capsules are more effective than pills, and red colored pills work better than blue ones.