The Placebo Effect 1955 – The Mind's Role in Treatment

Today, the term placebo generally refers to a perceived or real improvement in patients following a method believed to be effective, such as a sham medicine or procedure. The placebo effect highlights the importance of patients' expectations and brain health, particularly for subjective outcomes such as pain levels.

The best-known account of the placebo effect was documented in 1955 by American physician Henry Beecher: during World War II, saline injections given to soldiers when morphine supplies ran out provided substantial pain relief. 

One mechanism of the placebo effect involves endogenous opioids, the natural painkillers produced by the brain, and factors such as the activity of the neurotransmitter dopamine. When mice were given an immune-suppressing compound together with a sweet chemical, they became conditioned over time, and immune suppression was observed even when only the sweetener was given. This suggested that conditioning might play a role in human placebo responses. 

A placebo presented to people as a stimulant can increase blood pressure, while alcohol placebos can produce a feeling of intoxication. The color and size of medicines make a significant difference to their perceived effectiveness. The placebo effect varies between the populations and countries in which it is tested. The nocebo effect occurs when patients believe a medicine will cause side effects and experience some of the side effects they expect, even when given a pharmacologically inactive medicine (commonly called a "sugar pill"). 

Description of the Article Image: Because a person's expectations influence the placebo effect, a pill's color, size, and shape all affect the placebo response. Red pills work better as stimulants, while pills in "cool" colors work better as depressants. Capsules are generally perceived as particularly effective.

Historical Figures Mentioned in This Article: Henry Knowles Beecher (1904–1976)

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