Guest:

• Anne Harrington, Harvard professor for the history of science and author of "The Cure Within"

Everyone has heard about the placebo effect, but most people only think about the phenomenon – erroneously – in the context of sugar pills.

This singular focus may distract us from future research on "ways in which the placebo effect is a part of every medical intervention," says Anne Harrington, Harvard professor for the history of science and author of "The Cure Within."

Placebo surgery, for example, can provide measurable relief to patients.

In a landmark study, Dr. J. Bruce Moseley worked with a group of Korean War veterans who had been experiencing knee problems for years. He told patients that some of them would be getting surgery, but they wouldn't be told who. For the patients who did not get surgery, the doctor went through all the motions: calling for saline solution, making punctures in the knees - and then he did nothing else. He stitched the patients up, and they were released a day later.

Most patients - whether they'd had surgery or not - reported feeling a lot better. And even after patients learned that they'd received placebo surgery, they still reported increased mobility and reduced pain.

How are these effects possible?

Ceremony and ritual are ingrained in us and much older than modern medicine. "One of the most powerful rituals of medical intervention we have in Western medicine is surgery. It's scary and people put on masks and white gowns and you get wheeled in," says Harrington.

Clearly, there's much more to be learned about the placebo effect and the ability of medicine to tap into the power of the mind.

Still curious?

• "Expectations Influence Effects of Medications and Placebo"
• "A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee"