GC: n

S: NCBI – https://www.ncbi.nlm.nih.gov/books/NBK513296/ (last access: 2 February 2025); HHP – https://www.health.harvard.edu/newsletter_article/the-power-of-the-placebo-effect (last access: 2 February 2025).

N: 1. – placebo (n): early 13c., name given to the rite of Vespers of the Office of the Dead, so called from the opening of the first antiphon, “I will please the Lord in the land of the living” (Psalm CXVI.9, in Vulgate Placebo Domino in regione vivorum), from Latin placebo “I shall please,” future indicative of placere “to please”. Medical sense is recorded by 1785, “a medicine given more to please than to benefit the patient.” Placebo effect is attested from 1900.

– effect (n): mid-14c., “execution or completion (of an act),” from Old French efet (13c., Modern French effet) “result, execution, completion, ending,” from Latin effectus “accomplishment, performance,” from past participle stem of efficere “work out, accomplish,” from assimilated form of ex “out” (see ex-) + combining form of facere “to make, to do” (from PIE root *dhe- “to set, put”). From French, borrowed into Dutch, German, Scandinavian.

From late 14c. as “power or capacity to produce an intended result; efficacy, effectiveness,” and in astrology, “operation or action (of a heavenly body) on human affairs; influence.” Also “that which follows from something else; a consequence, a result.” From early 15c. as “intended result, purpose, object, intent.” Also formerly with a sense of “reality, fact,” hence in effect (late 14c.), originally “in fact, actually, really.” Meaning “impression produced on the beholder” is from 1736. Sense in stage effect, sound effect, etc. first recorded 1881.

2. placebo effect. Also known as: nonspecific effect.

• placebo effect, psychological or psychophysiological improvement attributed to therapy with an inert substance or a simulated (sham) procedure. There is no clear explanation for why some persons experience measurable improvement when given an inert substance for treatment. Research has indicated that the effect may be caused by the person’s expectations about the treatment rather than being a direct effect of the treatment itself.
• One of the first doctors to deliberately prescribe placebos, or inert treatments, was Scottish physician William Cullen, who mentioned in a lecture series in 1772 having given placebos to patients to appease them, not to cure their conditions. Despite Cullen’s observations that placebos appeared to produce beneficial effects in some patients, the term placebo effect was not introduced into medicine until the early 20th century.

3. In modern medicine, placebos, including inert drugs and sham procedures, are frequently used in clinical trials that are designed to test new treatments, particularly those developed for neurological and psychiatric conditions. In placebo-controlled trials, enrolled patients are randomly and unknowingly (blindly) assigned to receive either the new medical intervention being tested or a placebo. This prevents patients from knowing what treatment they received, which could cause them to influence study results, and it allows researchers to determine whether the new intervention produces an effect greater than that of the placebo.

The use of placebos in clinical trials has raised important questions in medicine and bioethics. The World Medical Association’s (WMA’s) Declaration of Helsinki, which provides a set of ethical guidelines for medical experimentation on humans, traditionally prohibited the use of placebos in trials when effective therapies or interventions already existed. In 2001, however, the WMA revised its guidelines to allow placebo-controlled trials under certain circumstances, such as when scientific methodology required the use of a placebo or when a new intervention was tested for a relatively minor health condition.

4. Clinical Psychology; Medication: placebo effect.

• The effect on a patient’s health status (improvement or worsening) that may occur due to the patient’s expectation that a particular intervention will have an effect.
• The placebo effect is independent of the effect being studied (pharmacological, surgical, etc.). When a placebo is given to the control group, both groups will experience this effect, making it possible to isolate the specific effect of the intervention.
• placebo effect: term and definition standardized by the Health Technology Assessment (HTA) Glossary English Editorial Board and the Translation Bureau (Canada).

S: 1. Etymonline — https://www.etymonline.com/search?q=placebo+effect (last access: 2 February 2025). 2 & 3. EncBrit – https://www.britannica.com/science/placebo-effect (last access: 2 February 2025). 4. TERMIUM PLUS – https://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&srchtxt=PLACEBO+EFFECT&index=alt&codom2nd_wet=1#resultrecs (last access: 2 February 2025).

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CR: clinical pharmacology, disease, drug substance, clinical pharmacology, drug therapy, medication, medicinal, pharmacology, placebo, treatment.