A Harvard anesthesiologist coined the phrase the "placebo effect," after he discovered that injections of a saline solution helped wounded soldiers in World War II overcome pain once the morphine ran out. Now, a group of Oregon scientists are following in his footsteps as they begin mapping what they call the "expectancy effect" ? the impact on health of a person's expectations of getting well.

Up to 35% of a therapeutic response to any medical treatment could be the result of belief, Oregon researchers hope to show that a patient's expectation of getting well can have a positive affect on their health outcome.

The study's goal is to develop models that can be used to study cognitive and physiological changes that contribute to the expectancy effect.

The models could range from "perceived self-efficacy" ? the belief that a person can influence his or her own health ? to hormonal activity and genetic changes that affect the brain's neurotransmitter systems. The researchers also hope to improve the design of clinical trials by learning how individual differences contribute to changes in their responses to medical treatments.

The expectancy effect is related to the placebo effect, in which a patient reports a positive response to an inactive medical treatment, such as a sugar pill, as if it were an active medical treatment.

But the expectancy effect is broader than the placebo effect and includes all processes and influences that may affect the brain's anticipation of a response.

We're not talking about patient-physician interaction, which, to some people, is considered part of placebo effect ? the contact, the handholding, the bedside manners. We're really thinking about people's hope or expectation that they're going to get better.  For example, one recent study showed that Parkinson's disease patients who were administered a placebo experienced changes in brain chemistry similar to those caused by symptom-treating drugs levodopa and apomorphine.

Do you realize how huge this is? It means that the medicine your doctor gives you is probably not effective beyond your belief in it. But beyond that, these studies show the amazing powers of our brains. The healing does not really occur because of the drug but because of our faith in the doctor and in the drug. Faith healing? It's really not that different!!