Dec. 23, 2010 -- Could you be healed by the power of a placebo drug—even when you know it's a fake?
It might sound strange to some, but a new study published in the most recent issue of PLoS One may have turned the conventional idea of a placebo on its head. Researchers found that placebo pills benefited patients, even when doctors explained that they were only taking sugar pills.
"Until now, doctors have thought they had to lie about the placebo pill in order to tap into the effects," said Dr. Ted Kaptchuk of Harvard Medical School and Beth Israel Deaconness Medical Center in Boston. "But we said, 'Let's see if placebos can work when they're applied in an honest way.'"
And, according to this study, it seems they did.
Researchers divided 80 study participants who suffered from irritable bowel syndrome, or IBS, into two groups. One group received no treatment for their condition while the other received sugar pills that they took twice a day.
Three weeks later, 59 percent of study participants who knowingly took the placebos reported reduced symptoms and adequate relief for their IBS symptoms, while only 35 percent of the control group reported similar results.
The placebo effect has long been based on positive thinking, with people taking fake pills that they believe to be real.
"I was hopeful from the beginning," said Kaptchuk. "I thought [the study] would work and it would be very subversive."
Half of American Doctors Gave Placebos to Patients
The motivation for the study came on the heels of a 2008 survey published in the journal BMJ which found that half of American doctors had given their patients placebos in place of actual medication.
When asked whether they had used placebos for psychological benefits in the patients, most doctors responded yes in the 2008 survey.
This practice goes against advice from the American Medical Association, which discourages placebos in a clinical setting, unless the patient is aware and agrees to it.
But physicians said this should not take away from the importance of placebos, as they can benefit a patient's well-being and help test new medicines in randomized trials.
Placebos and Randomized Trials
But Kaptchuk said placebo randomized trials can be confusing for patients, as well.
"When someone is in a study where they know they may be taking a placebo, they live in ambiguity," said Kaptchuk. "There's always that worry that they're feeling better but then [there's] the question, 'Well, what if I'm just on the placebo?'"
Changing Chemicals in the Brain
Dr. Jon-Kar Zubieta, a professor of psychiatry and radiology at the University of Michigan Medical School, has done extensive research on placebo effects in the brain. Zubieta said there are known physiological effects that happen while taking a placebo and going through the ritual of medicine.
"When patients receive a placebo in the context of pain, the brain releases chemicals including dopamine and endorphins that can improve the pain and emotional state in subjects," said Zubieta. "But it was somewhat surprising to me that they had a strong placebo effect even when disclosing it."
Kaptchuk said that researchers made it clear that the pills had no active ingredients, even going so far as to print 'placebo' on the pill bottles.
But according to the study, patients were told that "placebo pills, something like sugar pills, have been shown in rigorous clinical testing to produce significant mind-body self-healing processes."
Zubieta said that patients may have had an expectation of improvement after hearing that placebos showed 'self-healing processes.'
"You're telling them they're receiving an inactive substance, but you're also telling them that they might get better," said Zubieta. "I'd like to know how much of that expectation affected the improved outcomes."
In the study, authors noted some limitations, which included a relatively small sample size and a short trial duration which would make it difficult to estimate long-term results.
Plus, the improvements were self-reported. Placebo effects on pain and depression are often measured through PET and MRI scans, imaging techniques that measure chemical and metabolic changes in the brain. But when the improvements are measured by the patient, Zubieta said it lacks the objective measure to be sure of the results.
Positive Effects of Placebos
Dr. John Clarke, assistant professor of medicine in the division of gastroenterology at Johns Hopkins School of Medicine, said that the proactive and regimented nature of taking a placebo may in itself be related to improved symptoms.
"Some remedies of IBS are just stress reduction, so if giving people a placebo decreases their stress level and makes them feel proactive, then you could argue that it's working," said Clarke.