English, Genel Kültür

The Placebo Effect

The placebo effect is the beneficial influence of a treatment that has no medical value. A sick person injected with salt water or given a sugar pill often feels better nonetheless. This result is especially true for subjectively assessed disorders such as migraines, back pain, and depression. The placebo effect may account for a large part of the therapeutic value we ascribe to medications.

The placebo effect for pain medications has been at least partially explained by brain chemistry. When the brain experiences pain, it releases endorphins —chemicals that naturally act like morphine to relieve pain. Brain imaging studies have shown that when a person takes a placebo in the belief that it is a drug, it triggers the release of endorphins. Neurologically, it’s as if the person had actually taken a drug.

There is also the less understood but equally powerful nocebo effect. Often, when people are told that they are going to experience negative side effects from a drug, they do, even if there is no medical reason for it. In one study, people were given a sugar pill and told that it induced vomiting. Later, 80 percent of them started throwing up. Similarly, in another study, women who believed they were going to die of a heart attack were found to be four times more likely to die of a heart attack than women with the exact same medical profile who did not think they were at risk.

Thinking sick may make you sick. In some realms of medical treatment, the placebo effect actually seems to be getting bigger. In studies of antidepressants, the response rate to placebos has been increasing by 7 percent every ten years. In 1980, 30 percent of depressed people given a placebo improved without any other treatment; in 2000, it was 44 percent. This change may be due to widespread advertising and heightened expectations for drugs. In general, the public has more faith in psychiatric medication than it did twenty years ago, which gives placebos more power.


  1. The color of pills may also have an effect on some patients. In one Italian study, blue placebos made excellent sleeping pills for women but had the opposite effect on men.
  2. Painful injections may have more therapeutic value than ones that hurt less.