MYTH #6: The Placebo Effect Is Negligible
Tell that to your brain, though it probably won’t believe you.
The word placebo, from the Latin for “I shall please,” first turned up in medical texts in the 18th century, defined as a treatment intended to make a patient happy rather than do any actual healing. So why do placebos sometimes work?
Placebos are often called sugar pills, and indeed, they’re sometimes tablets made of sugar or starch, though a placebo can be any form of faux medical therapy or treatment made to look like the real thing. Scientists include placebo groups in clinical trials thanks to the work of anesthesiologist Henry K. Beecher, MD. In 1955, Dr. Beecher analyzed 15 studies in which patients with various diseases had received placebos and found that about 35 percent of them responded as though they had received real treatments.
This finding had major implications for the study of new drugs and other therapies, since it suggested that about one-third of sick people get better if they think they’re receiving treatment. As a result, when scientists conduct a clinical trial of a new drug or therapy today, they have to account for the placebo effect. An experimental therapy is usually considered a flop if it fails to treat significantly more than 35 percent of the patients who receive it.
Some recent studies have cast doubt on Dr. Beecher’s 35 percent rule and on the concept of the placebo effect in general. However, studies show that placebo treatments are surprisingly effective for a variety of conditions, including Parkinson’s disease, depression, and gastrointestinal problems such as irritable bowel syndrome. Conditions with the highest response rates tend to be those with symptoms that are difficult to quantify, such as pain.
Skeptics claim that any response to a placebo is “all in your head.” They’re right, in a sense. Sophisticated medical imaging shows that people given placebos experience significant changes in brain chemistry. At least 30 studies have shown that when people who are experiencing some form of pain are told they will receive a pain reliever but are given a placebo instead, their bodies nonetheless produce morphine-like compounds called opioids.
More important, placebos seem to diminish pain. In one study, researchers applied heat to the skin of volunteers until it hurt. Then they slathered a phony cream on the sore skin, telling the volunteers that the salve contained soothing medication. More than 70 percent of the volunteers said the placebo cream relieved their pain.
“The brain has the capability to exert control over the rest of the body, but we really don’t know how it works,” says Columbia University research psychologist Tor D. Wager, PhD, who led the study.
The placebo effect appears to go beyond pain reduction. For instance, in a recent experiment, asthma patients who believed they were receiving the drug salmeterol but were given placebos not only felt better but also had improvement in their lung function, though not as much as people who received the real drug.