The Nocebo-The Placebo's Evil Twin

Honesty is harder when the truth risks harm.

People taking sugar pills and other faux medications with inert ingredients for such symptoms as pain, dizziness, headache, and depressed mood often experience relief. The placebo effect is well known. The placebo's evil twin is the nocebo-it comes from a Latin word meaning I will harm-and it has recently gotten more attention from researchers. The Harvard Mental Health Letter reports 20 percent patients taking sugar pills in clinical drug trials spontaneously report unpleasant side effects-and even more describe unpleasant effects if they are asked.

Expectations matter. If we expect help, we may feel better. If we expect distress we may feel it. And these physical manifestations are real, not imaginary. The Harvard letter reports on an experiment in which volunteers were told a mild electric current would be passed through their heads and that they might experience headaches. There was no current, but two thirds of the volunteers got headaches.

A New Yorker story by Gareth Cook reports that people involved in clinical drug trials often experience the symptoms they are warned about even when they are taking placebos. In research on fibromyalgia treatments, the story says, eleven percent of the people taking sugar pills dropped out of the trial because of debilitating side effects.

People also experience the nocebo effect as a result of disasters and scary information, alarming news and rumor. After the 1995 saran gas attack in a Tokyo subway many people who had actually not been exposed to the nerve gas suffered the highly publicized symptoms of dizziness and nausea. A New York Times story by Paul Enck and Winifred Hauser tells of a participant in a clinical trial for an antidepressant drug who attempted suicide by swallowing 26 pills. The person's blood pressure plunged dangerously even though the pills swallowed were harmless.

Sometimes the same treatment can be both placebo and nocebo. The Harvard letter tells of volunteers who experienced symptoms when told an injection contained an allergen, and relief when told an injection would neutralize the symptom. In both cases the injection contained only salt water.

Informed consent is a powerful doctrine that obligates physicians to tell patients all the risks of treatments. But what if all that information is detrimental to the patient? A Boston Globe story by Chris Berdik reports some reflections by doctors, all of whom urge honesty combined with the kind of thoughtful and skilled communication that takes some time with the patient. Dr. Luana Colloca, a researcher at NIH who studies placebos and nocebos, describes positive framing-you can say that two percent of the people on this treatment had nasty side effects, or that 98 percent did not. The Times story emphasizes that a doctor's choice of words is important. The story quotes the cardiologist Dr. Bernard Lown who once said, "Words are the most powerful tool a doctor possesses, but words, like a two-edged sword. can main as well as heal."