PORTLAND, Ore. - It's a question scientists have debated for more than 50 years: Can a person's belief or expectation of overcoming an illness improve that person's overall health?

　　While this so-called "expectancy effect" may not necessarily influence the underlying cause of a disease, evidence suggests it can have an impact on a patient's health outcomes. A new, National Institutes of Health-funded research program at Oregon Health & Science University aims to find out why.

　　The Oregon Center for Complementary and Alternative Medicine in Neurological Disorders (ORCCAMIND) in the OHSU School of Medicine has received a three-year, $2.4 million grant from the NIH's National Center for Complementary and Alternative Medicine to develop "Complementary and Alternative Medicine: Expectancy and Outcomes," or CAMEO.

　　CAMEO's goal is to develop expectancy effect models that can be used to study cognitive and physiological changes contributing to the phenomenon, ranging from perceived self-efficacy - the belief that a person can influence his or her own health outcome - to hormonal activity and genetic changes that affect the brain's neurotransmitter systems, such as dopamine, serotonin and opioid, said Barry Oken, M.D., professor of neurology and behavioral neuroscience in the OHSU School of Medicine, and director of ORCCAMIND and CAMEO.

　　Researchers also hope to improve the design of clinical trials by heightening understanding of how individual differences contribute to the variability in responses to medical interventions.

　　Expectancy effect is considered a component of placebo effect, a long-studied medical outcome stemming from any clinically prescribed, biologically inert substance or inactive procedure for which there is no direct biological effect, including words, pills, gestures, devices and surgery. Expectancy effect is considered more broad and includes all processes and influences that may affect the brain's anticipation of a response.

　　"We're not talking about the patient-physician interaction, which, to some people, is considered part of placebo effect - the contact, the handholding, the bedside manners," said Oken, who wrote a chapter about placebo effect in his 2004 book, Complementary Therapies in Neurology: An Evidence-Based Approach. "We're really thinking about people's hope or expectation that they're going to get better."

　　One recent study, for example, showed Parkinson's disease patients who were administered a placebo experienced changes in brain chemistry similar to that caused by symptom-treating drugs levodopa annd apomorphine.

　　"It's really pretty remarkable," Oken said. "In Parkinson's patients, you can show dopamine release in the basal ganglia with administration" of the placebo.

　　CAMEO will focus on four areas: Parkinson's disease, metabolic syndromes, Alzheimer's disease and a mouse model for multiple sclerosis, Oken said. Each area is led by a two-person team that includes a conventional medicine physician and a complementary medicine practitioner. The grant allows ORCCAMIND to build on relationships it established with the National College of Naturopathic Medicine, the Oregon College of Oriental Medicine and Western States Chiropractic College in Portland.

　　NCCAM developmental centers, such as CAMEO, "clearly require close affiliation with CAM centers because part of the goal was to facilitate development of research infrastructure at the CAM institutions," Oken said. "So each of the four projects is linked."

　　Working with complementary practitioners is important because many of them have "succeeded in harnessing this effect," Oken said. "From my point of view, they have a much better handle on how to maximize this effect than conventional practitioners."

　　The research teams also will study factors that may contribute to clinical benefit from expectancy effect, including stress and personality traits.

　　One area of the brain that CAMEO will examine closely is the hypothalamic-pituitary-adrenal axis, a cluster of neuroendocrine components that includes parts of the hypothalamus, the anterior lobe of the pituitary gland, adrenal glands and hormone-transporting systems. The axis controls reactions to stress and is believed to be linked with mood disorders.

　　"The HPA acts as sort of a stress mediator," Oken said. "Those kinds of things might predispose a person to have a better, bigger response (to placebo) than others."