In 1961 physician Walter Kennedy coined the word nocebo, Latin for I shall harm, to describe harm that comes from a patient’s expectations of an inert treatment rather than from any drug. This episode explains how anticipating pain triggers the release of cholecystokinin, which amplifies pain signals, and why there is no evidence of a gullible personality type. The numbers are striking: a 2022 meta-analysis of COVID-19 vaccine trials attributed 72 percent of adverse effects after the first dose in the placebo groups and 52 percent after the second to the nocebo effect.

The hosts look at the 2013 statin scare in the United Kingdom, when media coverage of side effects led many patients to stop their medication and was followed by an estimated 2,000 additional cardiovascular events. They cover dropouts from placebo arms of Parkinson’s and depression trials, electromagnetic hypersensitivity, theories about Havana syndrome, and culture bound curses such as pointing the bone. The episode ends with the ethical bind doctors face when informing a patient can itself cause harm.

• Almost 9 percent of Parkinson’s patients and 1 in 20 depression patients quit trials while taking inert pills
• In 1973 G. W. Milton at Sydney Hospital described melanoma patients who declined and died soon after hearing their prognosis, comparing it to bone pointing
• Stewart-Williams and Podd argue that placebo and nocebo can describe the same mechanism, such as immunosuppression, judged good or bad
• Framing helps: 95 percent of patients tolerate this drug instead of 5 percent get joint pain
• Authorized concealment lets patients consent in advance not to be told about mild side effects