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.
Often a doctor will diagnose one illness and prescribe drugs for it, and the patient will get better, only to discover later that the original diagnosis was wrong. The treatment didn't have the desired medical effect, but the placebo effect worked - at least temporarily. Doctors must take care not to let a patient's placebo effect lull them into a false sense of confidence in their diagnosis, he says.
Dr. Redelmeier says he'd never prescribe a false treatment, but believes it's sometimes all right to let people try their own placebos. For example, he had a patient with insomnia who couldn't take regular sleeping pills because of his lung disease. When the patient asked whether a glass of warm milk at bedtime might help, Dr. Redelmeier didn't discourage that tactic, even though it's not scientifically proven to help.
That, he says, is as far as he can go without crossing ethical lines. "You've got to avoid deceiving the patient or yourself," he says.
The placebo effect
A Danish study in 2001 rocked conventional wisdom by analyzing 114 placebo-controlled trials and suggesting the placebo effect is a myth - people who get no treatment generally improve just as much as those who get placebos, researchers said. But a growing body of research into the mind-body connection suggest that placebos could indeed have healing power all their own:
In 1955, Henry Beecher, chief of anesthesiology at Massachusetts General Hospital in Boston, published a paper called The Powerful Placebo. He reviewed 15 placebo-controlled trials and determined that placebos work as well as standard medicine about 35 per cent of the time.
In a 1997 Canadian study of benign enlargement of the prostate gland, more than half of the men who received a placebo tablet not only felt better, but showed physical improvement such as easier urination. Participants given the placebo also complained of negative side effects, such as impotence and nausea. This is known as the "nocebo" effect.
A 2002 U.S. study followed 180 patients with knee pain. Some underwent surgery and some received simulated surgery - small incisions were made but they weren't actually operated on. There was no difference between the two groups in terms of pain relief and knee function.
A 2005 study reported in the Journal of the American Medical Association shows that fake acupuncture - inserting needles shallowly and at random - works just as well as real acupuncture at relieving migraines.
A survey of 231 Chicago-area physicians revealed that almost half use placebos in their clinical practice.
FREQUENCY OF PLACEBO USE
Forty-five per cent of respondents had used a placebo for clinical care.
When asked how often in the last year:
One to 10 times: 15%
More than 10 times: 85
Not at all: 22%
When asked about the practices of other physicians and nurses, 80 per cent of respondents believed their colleagues used placebos during routine care:
CIRCUMSTANCES OF PLACEBO USE
Respondents were asked the reason for their use of placebos.
To calm the patient: 18%
As a supplemental treatment: 185
After an "unjustified" demand for medication: 15%
For non-specific complaints: 13%
After all treatment possibilities were exhausted: 11%
To control pain: 6%
To get the patient to stop complaining: 6%
As a diagnostic tool: 4%
INFORMATION GIVEN TO PATIENTS
Respondents were asked how they verbally introduced the placebo to the patient.
As a substance that may help and will not hurt: 34%
As medication: 19%
As medicine with no specific effect: 9%
As a placebo: 4%
"This may help you but I am not sure how it works.": 33%
SOURCE: RACHEL SHERMAN AND JOHN HICKNER, JOURNAL OF GENERAL INTERNAL MEDICINE