If placebos work, should doctors use them?
Most people think of placebos as harmless "sugar pills" given in clinic trials to some participants so that medical researchers can gauge the effects of the real drug on others. But in some trials, the "placebo effect" proves to be as strong as that of the drug. Consistently 30 percent or more of the subjects given placebos will show some improvement by taking the dummy pills.Skip to next paragraph
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So over the decades a small band of researchers has taken a hard look at those pills. Are they really effective? Should they play a role in medical therapy?
A landmark study in 2001 concluded that they weren't useful. It "found little evidence in general that placebos had powerful clinical effects," the New England Journal of Medicine (NEJM) reported.
But that hardly put the matter to rest as new studies emerged. A March article in The New Scientist summed up the problem: It listed the placebo effect as one of "13 things that do not make sense" to science.
Today the definition of placebo effect has broadened beyond dosing with inert pills to include questions about whether healing is still in part an "art" and issues such as how the relationship between doctors and patients affects treatment outcomes. In its last fiscal year, the National Institutes of Health approved 14 clinical studies that aim to better measure and understand the placebo effect. Some of the most exciting work for scientists has come when they have scanned the brain and measured actual biochemical effects of placebos at work.
Among the placebo studies that have been reported since the NEJM article:
• A report in the journal Psychosomatic Medicine earlier this year showed that patients with problem coughs who were given a placebo (a dose of Vitamin E) significantly reduced their coughing compared with a group of similar coughing patients who received no treatment.
• Heart patients who faithfully took either a heart medication or a placebo fared equally well, according to an article in the journal Nature last November. The authors theorized that the faithful taker of a drug or placebo might also be faithful in following other recommended routines, such as dieting or exercising, which were creating the real benefit. Or, more controversially, they said, the study might also suggest that a patient could be as well off taking a less-expensive placebo as taking a drug.
• In an April 2004 study reported in the Archives of General Psychiatry, 20 Parkinson's patients received surgery in which human dopamine neurons were transplanted into their brains. Twenty other patients received "sham" surgery, in which nothing was transplanted. Neither the patients nor the medical staff knew what each patient received (the "double blind" standard). After a year, those who declared themselves better, and those whom the staff concluded were improved, came from both the treated and nontreated groups.
• In an experiment published in the journal Science last year volunteers were subjected to a harmless but painful electrical shock. When they were told that they had had an antipain cream applied to the site (really an inert placebo), they rated the pain as less intense. What's more, brain scans showed that areas of the brain associated with pain indeed were less active.
The study suggested a practical use of the placebo effect by doctors, said one of the researchers. If you share your expectation that a drug will work with your patient, "you enhance the effect," he concluded. But if a doctor said, or even hinted, that his treatment might not be effective, "it would be much less likely to be effective," the researcher said.
In Israel, 3 of 5 doctors surveyed reported using placebos in their practice at least once a month. And 94 percent said the inert pills were effective to some degree, according to a study reported in the British Medical Journal last year. "Clearly wider recognition of [placebo use], and debate about its implications, are needed," the Israeli researchers said.
But is that honest? To most practitioners of Western medicine, dispensing sugar pills or using "sham" surgery in actual practice teeters on the edge of unethical practice. They view it as withholding real treatment and as establishing a deceptive relationship between doctor and patient.