Doctors may be able to invoke the same benefits of placebos without the deception.

THE GIST

Even when patients know they're just taking a placebo, they can still see an improvement in their symptoms.

Doctors sometimes prescribe actual drugs to patients just for the placebo effect, even if they don't think the particular drug will help the patient.

The placebo effect could be the result of the doctor-patient relationship and the "exchange of healing symbols," according to one researcher.

A fake pill can make patients feel better, even when they know it's nothing but inert ingredients, according to a new study.

It has been known for decades that patients taking a dummy pill or receiving a fake treatment they believe is real can still show improvement of their symptoms. This placebo effect is strong enough that more than half of doctors admit to prescribing drugs strictly to capitalize on the patients' placebo reaction to taking a pill.

But this practice raises ethical questions, nor can doctors prescribe fake pills while telling a patient they are taking a real drug.

A new study shows that there may not be need for deception. In certain situations, doctors may be able to invoke the same benefits of placebos even if the patients know they are taking a pill with no active ingredients.

"There's a universal belief in medicine that placebos are only effective if you fool the patient into believing they are receiving the medicine," said Ted Kaptchuk at Beth Israel Deaconess Medical Center and Harvard Medical School in Boston. "We decided to test if this is true. Do you really have to lie to get a placebo effect?"

The study involved 80 volunteers with irritable bowel syndrome (IBS), half of whom were assigned to receive no treatment while the other half received placebo pills.

The pills were presented as "placebo pills made of an inert substance, like sugar pills, that have been shown in clinical studies to produce significant improvement in IBS symptoms through mind-body self-healing processes." (This description was true.)

The patients were also told that the placebo effect is powerful; that the body can become conditioned to respond to placebo pills like Pavlov's dogs were conditioned to salivate at the sound of a bell; that a positive attitude helps but is not necessary; and that taking the pills faithfully is crucial.

"We built up expectations in the sense that we explained that the placebo effects are real, they happen automatically and you don't have to believe in them," Kaptchuk said. "We also tried to suspend the patients' disbelief."

After three weeks, 59 percent of placebo-takers said they had adequate relief of symptoms while 35 percent of the no-treatment group said they had adequate relief, according to the study, published today in the journal PLoS ONE.

"We don't think our study is definitive or is strong enough to change clinical practice" Kaptchuk said. "We have to replicate this is a larger sample of patients over a longer period of time."

"We don't think this would ever apply to shrinking a tumor or increasing the memory of a patient with Alzheimer's," he added. But for illnesses, such as irritable bowel syndrome, depression, fibromyalgia or lower back pain, where the severity of the symptoms is judged by the subjective report of the patient, placebos could be useful.

"Very strong evidence shows that when placebos change one's experience of symptoms, there are changes in the body," he said. The body can produce measurable changes in endorphins which reduce pain, for instance, and areas in the brain that modulate pain become active.

But how does it work if patients know what's happening? It could be an effect of the doctor-patient relationship and "the exchange of healing symbols," Kaptchuk said.

"From my perspective, this is not a nonspecific effect. This is the specific effect of the ritual of medicine," Kaptchuk added.

The doctor-patient interaction between the placebo and no-treatment groups was the same, and both groups got better, so some effect may have come from the patient's sense of being cared for. But the pill created a stronger effect.

"My hypothesis is that the doctor-patient relationship is enhanced by the patient twice a day taking something, reminding them that they're being supported by a caring physician," Kaptchuk said.

"Although several studies suggested that placebos can be equally effective without deception, this is the first rigorous study that provides scientific evidence for this," said Fabrizio Benedetti of the University of Turin Medical School, Italy.

"I believe this paper is a further confirmation that placebo effects are intriguing phenomena that help us understand the mind-body interactions," he added, "However, it is important to be aware that there is not a single placebo effect but many, with different mechanisms and in different systems and conditions."

For example, in some cases the patients' expectations are crucial to the effect. In other cases, genetics make a difference, Benedetti said. Learned responses can also play a role, he added.

"The fact that a placebo procedure works in one condition doesn't warrant that it works in a different condition," he said. "The challenge for the future is to understand these complex interactions and exploit them ethically at the bedside."