Nov. 28, 2012 -- For many people with Parkinson's disease, depression affects quality of life more than the symptoms such as shaking, according to new research.
"At least 50% of people with Parkinson's have depression," says Michael S. Okun, MD, national medical director of the National Parkinson Foundation and professor of neurology at the Center for Movement Disorders at the University of Florida, Gainesville.
That was a main finding of the Parkinson's Outcomes Project, a report released today by the National Parkinson Foundation.
"The big news is how large of a role depression plays in Parkinson's disease, how under-diagnosed and under-treated it is," says Joyce Oberdorf, CEO and president of the foundation.
The impact of depression on the health of people with Parkinson's is nearly twice that of movement problems, the researchers found.
About 1 million people in the U.S. and more than 4 million worldwide have the disease. It is marked by tremors and difficulty with walking, movement, and coordination.
Beginning in 2009, the researchers evaluated the care of more than 5,500 patients, ages 25 to 95. They went to 20 Centers of Excellence in the U.S., Canada, Israel, and the Netherlands.
About 9,000 clinic visits were included.
The researchers looked at information about medications, referrals to specialists, and rates of depression and anxiety, among other information. The study will be ongoing.
Based on the results, the researchers made some recommendations.
Depression & Parkinson's Disease Details
Mood disorders are common among people with Parkinson's, the researchers found. Besides widespread depression, anxiety is common.
"We have become more acutely aware over the last few years that these non-movement factors are impacting people's quality of life," Okun says.
Doctors should screen people with Parkinson's for depression at least once a year, the foundation says. Patients are encouraged to report mood changes to their doctors. Family members are also encouraged to accompany them to doctor’s visits and to discuss any changes in patients’ mood.
Treatment with medications and talk therapy, as well as getting regular exercise, can help, according to the researchers. "People's quality of life can significantly improve," Oberdorf says.
It's important to realize, Oberdorf says, that the depression is part of the disease, a chemical phenomenon. "It's not, 'Oh, I have Parkinson's disease and I'm depressed,'" she says.
The depression, she and others say, is related to changes inherent in the disease, such as a decline in the brain chemical dopamine. It helps control the brain's reward and pleasure centers.