As a recent article in The Scientist demonstrates:
“Nocebo” (meaning “I shall harm”) is the dastardly sibling of placebo (“I shall please”). In a placebo response, a sham medication or procedure has a beneficial health effect as a result of a patient’s expectation. Sugar pills, for example, can powerfully improve depression when the patient believes them to be antidepressants. But, researchers are learning, the reverse phenomenon is also common: negative expectations can actually cause harm.
When Parkinson’s patients undergoing deep brain stimulation were told that their brain pacemaker was going to be turned off, symptoms of their illness became more pronounced, even when the pacemaker was left on.2 When people with and without lactose intolerance were asked to ingest lactose, but were actually given glucose, 44 percent of those with lactose intolerance and 26 percent of those without it still complained of stomach pain. And men treated for an enlarged prostate with a commonly prescribed drug and told that the drug “may cause erectile dysfunction, decreased libido, [and] problems of ejaculation,” but that these effects were “uncommon,” were more than twice as likely to experience impotence as those who were not so informed.
On paper, it sounds like psychobabble—a negative effect caused by a sham treatment based on a patient’s expectations—but it is a real biochemical and physiological process, involving pain and stress pathways in the brain. And mounting evidence suggests that the nocebo effect is having a substantial negative impact on clinical research, medicine, and health. More.
It most certainly does not sound like psychobabble to anyone familiar with the placebo effect (the best attested effect in medicine, by which people who expect to feel better are more likely to do so than people who do not).
This most informative, and long overdue, article shows that different brain channels convey the undesirable nocebo effect, by which we feel worse if we expect to, from the channels that convey the placebo effect.
Medical programs, settings, and public service messages often convey unwanted nocebo effects, because the role of the mind in promoting health is not clearly acknowledged and understood. Here’s an example:
In 1987, a team of doctors in Ontario, Canada, suspected that medical consent forms might actually cause harm. Using the chance occurrence of two different consent forms being used for the same drug trial, they compared patient reactions to the wording of the forms. The trial pitted aspirin against sulfinpyrazone, a medicine already approved to treat gout, as a treatment for chest pain. Patients at two of the three centers hosting the trial were informed that “side effects are not anticipated beyond occasional gastrointestinal irritation and, rarely, skin rash.” At the third center, patients’ consent forms did not mention gastrointestinal effects. Seventy-six patients out of 399 (19 percent) given the first consent form that mentioned GI irritation withdrew from the study, citing GI issues, compared to just 5 out of 156 (3 percent) who received the second form.
One suggested option is to accentuate the positive:
A 1996 study from the University of Ottawa in Canada, for example, described the benefits and risks of a vaccine to 292 people, who had never been previously immunized, using two different approaches. Those who were told the percentages of vaccinated individuals who remain free of influenza and have no side effects had fewer side effects and missed less work than those told the percentages of people who acquire influenza and have side effects following vaccination.
The article is a gold mine of information that could help health care professionals improve treatment settings. What the patient thinks is happening is part of what is happening.
See also: The Spiritual Brain.
Hat tip: Stephanie West Allen at Brains on Purpose