Doctors prescribe placebos more often than patients might imagine.
A survey of Chicago-area physicians found that 45 per cent report they have given a patient a placebo at least once, according to a study published in this month's Journal of General Internal Medicine.
Past surveys of Israeli and Danish doctors revealed that 60 per cent and 85 per cent, respectively, admit they've relied on the "placebo effect" to heal patients.
So, should patients worry about their doctors shamming them?
Maybe not. Though prescribing dummy pills is viewed as ethically shady, the placebo effect can work. Brain-scan research indicates that placebos trigger pain-relieving endorphins in the brain. Indeed, anyone who has ever felt better after taking cough syrup may have enjoyed the placebo effect - some studies suggest that sugar water is just as good at healing sore throats. Belief in medicine can contribute heavily to its success.
Doctors turn to placebos for a variety of reasons, according to the Chicago study, including to calm the patient, as a last resort when nothing else works, or simply to get a patient to stop complaining.
They are not necessarily handing out sugar pills disguised as real drugs, says lead researcher Rachel Sherman, a fourth-year medical student at the University of Chicago. A more common scenario is a physician who tells a patient to take ibuprofen for pain when nothing else has worked because "it might help, and it won't hurt."
Even if the doctor doesn't believe the drug will alleviate the physical symptoms, the placebo effect may make the patient feel better nonetheless.
Ms. Sherman - whose medical education, to this point, has included no mention of placebo use in clinical practice - says her survey of 231 physicians points to the need for more open discussion.
"Perhaps this is something that will become more widely acknowledged," she says.
Placebos are commonly used in clinical trials to determine whether a drug works. Research has shown that they will make people feel better about 30 per cent of the time - though that figure has been challenged recently - so new drugs have to beat the placebo's effectiveness, at least.
But prescribing placebos to patients on a daily basis is something entirely different.
Giving a placebo to an unaware patient is unethical, "even when you're deceiving the patient for what you believe is their best interest," says Jeff Blackmer, an Ottawa spinal-cord-injury specialist and director of ethics for the Canadian Medical Association.
A few decades ago, Dr. Blackmer says, physicians played a more imperious role in patients' lives, and placebo use was more common - the old "take two aspirin and call me in the morning" school of thought.
But that era has ended; now doctors feel an ethical obligation to inform patients fully and get their explicit consent for every treatment. And placebos only work if patients don't know what they're getting.
"You can make a pretty coherent argument for the use of placebos, but the medical community has said that is outweighed by the obligation to disclose," Dr. Blackmer says.
But the placebo effect sometimes takes more subtle forms in the delicate dance between doctor and patient. Physicians try to win their patients' trust and boost their confidence in their own health, in part because they know that will make patients feel better. Just having someone listen to your problems and take them seriously can ease physical symptoms.
"It's not my style to give patients a fake drug and not tell them," says Michael Evans, a family doctor at Toronto Western Hospital. "But if you asked me, 'Do you use a placebo?' I'd say, 'Every day.' ... If I could prescribe one thing, it would be a positive outlook."
Donald Redelmeier, director of clinical epidemiology at Sunnybrook Research Institute in Toronto, says he doesn't believe most doctors prescribe placebos on purpose, but they sometimes stumble upon the placebo effect unwittingly.
