How telling people about the side effects of a drug can make them sick
Tests show people more likely to experience gastrointestinal trouble or erectile disfunction if told that it’s a side effect
The phrase “First, do no harm” doesn’t actually appear in the text of the Hippocratic Oath, yet it’s frequently considered a fundamental principle of medicine.
At the same time, we believe firmly in the principle of informed consent, the idea that people should know the risks of a drug or medical procedure.
But sometimes, trying to follow one of these principles violates the other.
Specifically, if you tell people that they are likely to experience a number of side effects, those people are significantly more likely to experience those side effects, according to Ted Kaptchuk, a professor of medicine at Harvard Medical School and the director of the Program in Placebo Studies at Beth Israel Deaconess Medical Center.
“Almost anything can be a side effect,” says Kaptchuk. And whatever side effects you tell a person are associated with a drug — dizziness, depression, dry mouth, drowsiness, insomnia, gastrointestinal trouble, foggy mind — “that’s what people get,” he says.
This effect is called a “nocebo” effect, a negative placebo. Instead of getting healthier because people expect to get healthier, they get sicker because they expect to get sicker.