Several studies have found that over half of all physicians have used placebos in their practice. Is there scientific validity to the prescribing of placebos? Dr. David Speigel, associate chairman of the department of psychiatry and behavioral sciences at the Stanford University School of Medicine, joins host Dr. Leslie Lundt to review the science behind placebos. Dr. Spiegel has extensively studied how psychological factors affect the brain's response to pain and illness.