Study to test the effectiveness of anti-depressants in treating symptoms of Parkinson’s disease

Sep 27 2004

A University of Rochester neurologist is heading a national research study to test the effectiveness of anti-depressants in treating some of the symptoms of Parkinson’s disease.

While Parkinson’s disease typically brings to mind symptoms such as tremors and slow movement, researchers have found that nearly half of all Parkinson’s patients also suffer from depression. While it might seem natural that someone who has a disease such as Parkinson’s might become depressed, it’s not so simple, says neurologist Irene Richard, M.D., who leads the study.

“Many patients 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 Richard.

“People diagnosed with other serious diseases that may also be disabling, such as rheumatoid arthritis, aren’t nearly as likely to become depressed.”

Richard’s study will evaluate common anti-depressant medications paroxetine (brand name Paxil) and venlafaxine (brand name Effexor) at treating the depression that patients experience. Richard says that until now, there hasn’t been a large placebo-controlled study to see how well anti-depressant medications actually work in patients with Parkinson’s. The 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 patients at 15 sites around the nation, including approximately 15 patients in the Rochester area. The four-year, $4 million study is being 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 groups of neurons in the brain that produce a chemical called dopamine. But cells that produce other brain chemicals such as serotonin and norepinephrine, which can play a role in depression, are also affected in people with Parkinson’s.

Of Parkinson’s patients 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, who is an expert on the psychiatric aspects of the disease. Patients 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, patients 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 patients with Parkinson’s disease.”

In addition to depression, some patients with Parkinson’s disease also become agitated or develop hallucinations, delusions, or confusion. Oftentimes the medications used to treat such symptoms worsen patients’ other symptoms. Richard’s colleague, Roger Kurlan, M.D., is leading a national study testing the effectiveness and safety of a medication aimed at helping people with Parkinson’s disease.

Anyone who has been diagnosed with Parkinson’s disease and is interested in participating in either study should call (585) 341-7500.