Parkinson's sufferers often depressed, study finds
Published: Wednesday, November 28, 2012 at 8:29 p.m.
Last Modified: Wednesday, November 28, 2012 at 8:29 p.m.
The largest study of Parkinson's disease to date shows that more than half of those with the disease suffer from depression — and it affects their quality of life more than the motor impairment characteristic of the disease.
The study, which is part of the Parkinson's Outcomes Project and is sponsored by the National Parkinson's Foundation (NPF), followed more than 5,500 patients in 20 centers of excellence in the U.S., Canada, Israel and the Netherlands. It started in 2009 and also is tracking patients' cognition and motor symptoms, medications and treatments and caregiver burden, along with depression.
Joyce Oberdorf, president and CEO of the Miami-based NPF, said that 3½ years ago, the NPF refocused its mission to improving quality of life in Parkinson's patients.
"We've long known that (Parkinson's) affects mood and mobility and is linked to things like heart disease," said Oberdorf. "We wanted to get at mood. We didn't intend to focus on depression. What our findings showed us is that it is much more important than we thought in gauging in how people are doing."
The study found that depression is more than twice as likely as motor degeneration to affect a patient's quality of life.
"We have noticed over the last decade that Parkinson's, though obviously a motor disorder, it's actually non-motor features that impact quality of life," said Dr. Michael Okun, the medical director of the NPF and the co-director of the Center for Movement Disorders and Neurorestoration at the University of Florida.
Okun, a neurologist, said changes in the brain brought on by Parkinson's can cause depression, likely at least in part because of the deficit of dopamine, a chemical in the brain associated with pleasure.
"Most people believe you're sad because you have Parkinson's, but actually neuro chemicals, electrical signals and degenerative changes in structures in the brain all have a link to depression in Parkinson's disease patients," Okun said.
"People shouldn't beat themselves up when they have depression … they should actually get help," Okun said.
The study found that between 45 and 75 percent of patients at the centers of excellence are already being treated for depression. UF has more than 600 participants in the study, such as Jeffrey Mackey, who has been treated for depression for a few years.
Although Mackey, 60, had suffered from depression since he was a teenager, it escalated with the onset of Parkinson's. At first his doctors didn't make the connection between the two conditions, but after he started being treated at UF, his neurologist told him to see a psychiatrist. Mackey went on antidepressants, and has felt better ever since.
"I feel like I'm floating on top of this depression now," said Mackey, who is an episcopal priest based in Melrose. "I'm not soaring anywhere, but I no longer tell my wife every day that I'm depressed. I say it maybe once or twice a month."
Okun said the study underscores a big need to screen and treat more Parkinson's disease patients for depression. The fact that the study showed high rates of depression at centers of excellence means that "even at the best centers, we're still under-treating this problem," Okun said. "I suspect the world has a real serious problem."
An estimated 4 to 6 million people suffer from depression worldwide, 1 million of those in the U.S., and about 85,000 people in Florida. Parkinson's disease is the world's second most common neurodegenerative disease after Alzheimer's disease. Depression also has been seen in Alzheimer's patients, Okun said.
The NPF recommends yearly screenings for depression in Parkinson's patients. "Our aim is to make everyone in the community aware of the importance of getting screened and treated for depression and that will make a significant difference in their lives," Oberdorf said.
Okun said the project is similar to one done on cystic fibrosis, in which patients were tracked daily at centers of excellence. "At some of the centers, patients were living longer, and in those centers, they were paying more attention to nutrition and lung function," Okun said, adding that when changes based on those findings were implemented at the other centers, patients' lifespans went from an average of 28 to 38 years.
Okun hopes the findings on depression could be used in a similar way. "These are real-world patients, and the findings are potentially directly applicable," Okun said. Unlike most studies, this one did not have exclusion criteria, so it included patients of all ages and stages of Parkinson's disease.
The project also is studying early onset of Parkinson's disease, different treatment styles at the centers of excellence, and disease outcomes in people who have lived with Parkinson's for a long time. Oberdorf said it will continue for at least another five years.
Another finding that has already emerged from the study shows that more than 90 percent of Parkinson's patients are still living at home after 10 years. According to Okun, this is a credit to good care.
"It's important to get expert care," he said.
Contact Kristine Crane at 338-3119 or firstname.lastname@example.org.