That pill your doctor just gave you? There's a decent chance that its ingredients are powerless to make you feel better—and that your doctor knows it. About half of U.S. doctors answering a recent national survey said that they sometimes prescribe placebo treatments to patients. That report, which appeared last month in the journal BMJ, has raised eyebrows and reignited a debate over whether such treatments have a place in medical practice. A January survey of Chicago-area physicians yielded similar findings.
Until around the 1960s, doctors routinely parceled out sugar pills, saline injections, and other inert substances that they presented to patients as real medicines. The placebos you might unknowingly get today are different: They're active agents such as over-the-counter pain medications, vitamins, antibiotics, and even sedatives. But, as with sugar pills, doctors have no evidence that these drugs can pharmacologically improve the patient's condition. Rather, the treatments are intended to promote positive patient expectations—otherwise known as the placebo effect.
While doctors may have the best intentions in mind, some experts worry that patients could interpret the use of placebos as deception—even if doctors are careful not to lie. "It's a fib by omission," says Frank Miller, an author of the BMJ study and a member of the senior faculty in the Department of Bioethics at the National Institutes of Health. "The healing relationship is heavily dependent on trust," says Robert Sade, a professor of surgery at the Medical University of South Carolina, who chaired the American Medical Association's Council on Ethical and Judicial Affairs in 2007. (The AMA issued a policy statement in 2006 advising doctors not to use placebos deceptively.) "Anything that undermines that trust is not good for patients."
Perhaps of more concern is that the medications that the BMJ survey found some doctors use as placebos, while generally benign, aren't without side effects. Over-the-counter painkillers carry some risk of ulcers; sedatives can be addictive and pose particular danger to the elderly; and misuse of antibiotics—which sometimes get doled out for colds despite having no power to kill the cold viruses, for example—can contribute to the development of antibiotic-resistant bacteria, a growing problem in the United States, says Howard Brody, director of the Institute for the Medical Humanities at the University of Texas Medical Branch in Galveston. In addition, using any kind of pill as a placebo is worrisome because it teaches patients that the right way to handle any symptom is by swallowing medication when some ailments might be improved by diet, exercise, and relaxation techniques, says Brody.
The powerful placebo. Other experts, however, see the widespread use of placebos as a virtue. Doctors' impulse to try to promote the placebo effect, if they think it might help and especially if they have little else to offer, is understandable, adds Jon Tilburt, an author of the BMJ study and an assistant professor of medicine at the Mayo Clinic in Rochester, Minn. "My belief is that this is an attempt of physicians to tap into the healing power of the mind," says John Hickner, coauthor of the Chicago survey and a professor of family medicine at the University of Chicago.
Scientific evidence accrued in the past decade has strengthened the idea that the placebo effect is a very real and potentially powerful phenomenon. In fact, studies of antidepressants and other medications indicate that roughly 20 to 30 percent of a treatment's benefit is typically due to the placebo effect, not from the treatment itself, says Tilburt. Some research even suggests that telling patients they're being given a placebo doesn't necessarily destroy the effect, notes Fabrizio Benedetti, of the University of Turin Medical School in Italy, who is one of the world's leading authorities on the science behind the phenomenon.
"It's pretty clear by now that the mind and the body talk to each other," explains psychiatrist David Spiegel, associate chair of psychiatry at Stanford University School of Medicine, who has researched the placebo effect. Brain scans have shown that by merely suggesting to patients that a treatment will work, such as by telling them that an inactive gel is actually a potent pain cream, doctors can get the body to release natural painkilling compounds and the brain to downshift its processing of pain signals.