The power of positive thinking appears to have tangible benefits for people with Parkinson's disease and could have broader implications, according to a new study co-authored by a University of Colorado associate professor.
Learning-related brain activity in Parkinson's patients improves as much in response to a placebo treatment as to real medication, according to the study, published in the journal Nature Neuroscience. It was co-authored by Tor Wager, an associate professor of psychology and neuroscience, and by researchers at Columbia University.
"I think there's so much hype around the fact that placebos work, that they do everything or they don't do anything at all," Wager said. "I think the truth sort of lies somewhere in between. It was surprising to me that the placebo effect and drug effects were very comparable."
Funded with "a couple of hundred thousand dollars" by the Michael J. Fox Foundation for Parkinson's Research, Wager said, the study shows how the placebo treatment — patients being led to think they have received medication, although they have not — works in people with Parkinson's disease by activating the dopamine-rich areas in the brain. Wager said the results underscore the power of expectations to effect changes in the brain.
"Many people know that dopamine is particularly important for Parkinson's disease, so we looked at the brain's response related to dopamine in regions of the brain, and we compared (results from) getting the sham medication to actually getting the real thing," Wager said. "And the interesting thing is that the improvements were just as large for the placebo as for the real medication."
Parkinson's patients are known to have trouble with what is known as reward learning, the brain's ability to connect actions with rewards, and to make motivated decisions in pursuit of positive outcomes.
For the study, the researchers used functional magnetic resonance imaging to scan the brains of 18 Parkinson's patients as they played a computer game that measures reward learning. Participants in the game discovered through trial and error which of two symbols was more likely to lead to a better outcome — either a small financial reward or simply not losing any money.
The Parkinson's patients played the game three times: when they were not taking any medication; when they took real medication dissolved in orange juice; and when they took a placebo, which consisted of drinking orange juice that they thought contained their medication.
Researchers found that the dopamine-rich areas of the brain associated with reward learning , the striatum and the ventromedial prefrontal cortex, became equally active when patients took either the real medication or the placebo treatment.
To Wager, the message from the study results are that psychological intervention — non-medicinal support — can be as important as the medicine that's ingested.
"It isn't just about drugs; it's about your level of optimism, what you believe you can do," he said. "We all need to know that how we encourage other people, and how we work with them, really matters — and how it really matters.
"From a medical perspective, there's a tremendous amount of money that goes into studying drugs, but drug companies and physicians alike don't really consider the role of the mind in that process at all."
Wager believes that positive emotional support — and encouraging activities that stimulate and challenge a patient -— could also have similar implications for those who suffer other neurologically related afflictions, ranging from chronic pain to depression and sleep disorders. Alzheimer's disease, he said, would be an exception.
"That's one disease where there's evidence out there that it (a placebo effect) doesn't work, and the reason is the systems in the brain that create placebo effects are damaged by Alzheimer's," Wager said.
To be clear, Wager and his colleagues are not recommending treating Parkinson's patients with placebos. What they do support is promoting things like cognitive therapy, social support and exercise, in addition to medication.
"These are things that are great across the board," Wager said. "What they do, in part, is they get people to experience new things and to engage in the world. I think the more of that you do, the better off you are."
Charlie Brennan: 303-473-1327, or