The placebo effect has long been the elephant in the parlor of medical research—in other words, an inconvenient truth. It occurs when someone’s belief in a remedy or in the power of a practitioner actually triggers an improvement in health.
A placebo (Latin for “I will please”) is a sham or simulated treatment, such as a dummy pill or “fake” procedure. As far back as ancient times it was known that the hope and expectation patients experience when treated—even with a placebo—by a trusted practitioner can play a large role in recovery.
It can be hard for researchers to tell how much the apparent efficacy of a real drug or procedure comes from the treatment or from the placebo effect. The only way to find out is to test treatments against a placebo in rigorously controlled clinical trials, in which neither the researchers nor the patients know who is getting the treatment and who is getting the placebo. If the treatment and the placebo work equally well, then the treatment itself had no therapeutic effect. Even with a treatment that is more effective than a placebo, a patient’s hope and positive expectations can add to its effectiveness.
It’s believed that anywhere from 10 percent to 40 percent of people given a placebo show some improvement for a variety of symptoms or conditions—notably pain, such as that from migraines or arthritis. Of course, placebos can’t cure cancer or other chronic diseases. Contrary to myth, when a condition improves via the placebo effect, that does not mean the problem was “just psychological.” When it comes to pain and many other phenomena, the mind and body work together.
Lately, researchers have been trying to find ways to use the placebo effect better in clinical practice. It’s now known that though a placebo is a “sham,” the physical responses to it are real—for instance, the release of brain chemicals and hormones or changes in the immune system. The brain not only senses pain, but can also release analgesic (pain-relieving) chemicals. This is probably one way the placebo effect works.
Placebos have a bad reputation because they can involve deception. If I prescribe sugar pills for patients with migraines, they may feel better for a while, but I have deceived them. A doctor is obliged to try to cure the ailment, not merely make the patient feel better. Honesty is the best policy: don’t prescribe placebos, but do explain the placebo effect. Acknowledge that healing is often a mysterious process and that the brain plays an important role.
Harnessing the placebo effect as a medical tool will take a lot more thought and research. Meanwhile, good practitioners— doctors, dentists, nurses and many others—already intuitively understand the ethical uses of the placebo effect as an ally in healing. In a way, it’s just another name for trust, optimism and hope. Their patients understand, too.
Originally published July 2010. Updated December 2013.