A placebo is an inert or innocuous medication, a fake medical treatment such as a sugar pill or a water injection that, by itself, has absolutely no medicinal effect. Although there is no biological or pharmacological reason for a placebo to be effective, nonetheless, a placebo can have a dramatic effect on health and behavior (Shapiro & Morris, 1978). The placebo effect is believed to be psy- chosomatic: The mind (psyche), rather than the placebo itself, has an effect on the body (somatic). The fact that an individual thinks or believes a medication is effective can be sufficient to cause a response to the medication.