Study Focuses on Depression in People With Parkinson's

11/30/04    Portland, Ore.

Doctors at Oregon Health and Science University are working with researchers around the country to test the effectiveness of antidepressants in treating some symptoms of Parkinson's disease.

While the best-known symptoms of Parkinson's disease are tremors and slow movement, researchers have found that nearly half of all Parkinson's patients also suffer from depression. Depression might seem like an obvious symptom of the disease, but doctors say it's not so simple.

"Many participants assume that's it's normal to feel this way. They might say, 'If you had Parkinson's disease, you'd feel this way too.' That's not true. If you treat the depression, they'll still have the other symptoms of the disease, but they feel better. It's very treatable," says neurologist Irene Richard, M.D., of the University of Rochester Medical Center, who is leading the national study. "People diagnosed with other serious diseases that may also be disabling, such as rheumatoid arthritis, aren't nearly as likely to become depressed."

Researchers will evaluate common antidepressant medications paroxetine (brand name Paxil) and venlafaxine (brand name Effexor) at treating the depression that participants experience. Parkinson's disease wreaks havoc in the brain and may cause such medications to work differently than they do in healthy people.

The study will include 228 participants at 15 sites around the nation, including 15 to 20 participants in the Portland metropolitan area. The four-year, $4 million study is funded by the National Institute of Neurological Disorders and Stroke.

Doctors estimate that about 1 million people in North America have the disease, which targets a small group of neurons in the brain that produce the chemical dopamine. But cells that produce other brain chemicals, such as serotonin and norepinephrine, which can play a role in depression, also are affected in people with Parkinson's.

Of Parkinson's participants who become depressed, about half have "major" depression that has a significant impact on their lives, while others have milder forms of depression that are still distressing.

"There's a huge amount of suffering out there due to the depression that comes so frequently as part of Parkinson's disease," says Richard, an expert on the psychiatric aspects of the disease.

Participants who have lost the pleasure they once took in activities or hobbies, or who are having difficulty sleeping or have a poor appetite, have common symptoms of depression.

"The depression is part of the illness, not simply a reaction to the disease. We've found that if a physician brings up the topic, participants will be honest and will discuss their depression, but oftentimes they won't bring it up themselves. We need to educate physicians to ask about this in their participants with Parkinson's disease."

Anyone who has been diagnosed with Parkinson's disease and is interested in participating in the study can call Michele Barnard at 503 494-1382.

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