However, Howard Brody, speaking at the annual meeting of the American Association for the Advancement of Science, also said that nowadays there are more ways to produce a placebo effect than just handing the patient a fake pill, ways that are not only ethical but also effective.
Brody, a professor of family practice at MSU and former director of the university's Center for Ethics and Humanities in the Life Sciences, said health care providers may appear to face an ethical dilemma: Should a placebo be prescribed and the patient lied to about what he or she is receiving, knowing that at least in some cases the placebo can be a powerful means of healing? Or should the provider carry out his or her ethical duty by telling the truth?
Fortunately, he said, the dilemma disappears because there are other ways to produce a placebo effect without using any form of "dummy" medication.
"This new way of thinking defines the placebo effect as a special kind of mind-body interaction that occurs in a health-care setting," Brody said. "Doctors may never prescribe placebos - dummy pills - but can make use of the placebo effect every time they see a patient. Seeing that the 'placebo effect' does not depend on the 'placebo' is key to making use of its healing potential in an ethical way.
"Features of the healing environment usually include a physician or healer that listens carefully to what you say and gives you a realistic and sound explanation of what is happening to you," he said. "People express care and compassion for your fears and suffering, and you leave feeling more in control of your life and your illness."
In addition, Brody said evidence exists that creating positive feelings in the health care environment goes a long way in treating a patient.
"Scientific studies have shown a link between all these elements of 'good healing' and persons feeling improvement in their symptoms and coping better with their illness later on," he said.
Brody said giving a patient a "dummy" pill and telling him or her it's a painkiller or antibiotic is "ethically suspect, if not blatantly unethical."
"Most patients, given a capsule or an injection and being led to think that the substance was a powerful painkiller or antibiotic, would feel tricked if they later discovered that it was really a sugar pill or a salt water solution," he said.
When it comes to using placebos in medical research, Brody said ethical problems are rarely an issue.
"Research subjects are routinely told of the way a trial is designed when they agree at first to be a part of the study - the so-called 'informed consent,'" he said. "Proper informed consent requires letting the subjects know that they might get either the 'real' medicine or a placebo. So no one suffers any unethical deception."
Placebos play crucial roles in medical research. Using a placebo with a control group lets researchers know if the "real" medication is working.
Also, in what are known as "double blind" studies, it's important the researchers do not know which subjects are getting real medication and which are getting placebos.