How the Placebo Effect Works

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Most of us only go to the doctor when we're not feeling well. You read old magazines in the waiting room, pony up your insurance company's co-pay, answer a stream of seemingly endless questions, and put up with being poked and prodded. And for enduring all of this, you expect something in return. More often than not, that something is a piece of paper with a prescription scrawled on it. You don't usually worry much about what's in the medicine that the doctor has prescribed, as long as it gets you feeling like yourself again. You trust that the doctor knows what's best.

But how much does that trust play into the healing process? What if, after filling that prescription and taking it faithfully, you found out that the medicine your doctor had given you wasn't proven to make you feel better? And yet you did get better. You expected to get well after taking those pills, so you did.

That's the gist of the placebo effect. It's what happens when a person takes a medication that he or she perceives will help, although it actually has no proven therapeutic effect for his or her particular condition. The medicine or treatment itself is known as a placebo, from Latin for "I will please." There are a few different types of placebos. They may be pharmacologically inert, meaning that they contain no active ingredients. These types of placebos often contain basic ingredients like sugar (hence the term "sugar pill"). Medications that do have active ingredients but aren't proven to work on the patient's particular condition can also be placebos. There have even been placebos in the form of surgery, injections and other types of medical therapies. Some people believe that complementary and alternative medicine count as placebos, too.

­Placebos have been shown to work in about 30 percent of patients, and they've been used by doctors for ages. In fact, they were often the only thing that a doctor could offer to relieve suffering, other than his or her attention and support. Some researchers believe that placebos simply evoke a psychological response. The act of taking them gives you an improved sense of well-being. However, recent research indicates that placebos may also bring about a physical response. In light of this, some people don't see anything wrong with a doctor prescribing a placebo. After all, he or she is doing it to help the patient. But others see the practice not only as harmful, but unethical, deceptive and possibly even illegal.

Although we've long known that placebos can work, we've only recently started to figure out how and why. On the next page, we'll look at some theories behind the therapeutic effects of placebos.