Parkinson's disease diagnosis can worsen depression

LOS ANGELES (KABC) -- Parkinson's disease is an incurable nervous system disorder that involves movement. Among the early symptoms are tremors and depression. The disease impacts millions around the world.

Parkinson's disease happens when nerve cells in the brain don't produce enough of an essential chemical. It has no cure. For many it can be a devastating diagnosis. In time, this disorder robs people of their ability to multi-task, react quickly and think fast.

Rapid-fire improvisation is a talent Robin Williams is famous for. Now we've learned the comic genius was faced with a neurodegenerative brain disease that would, as it progressed, ultimately slow him down.

Neurologist Grigor Harutunian says Parkinson's disease attacks the body's connection to the brain's main control center.

"The brain tells your arm to do something, and because of that dopamine transmission is slowed, it takes a while for you to get that. All these symptoms come because you're starting to lose dopamine," said Dr. Harutunian.

The goal of medication and therapies like deep brain stimulation is to replace the low levels of dopamine.

Ten percent of cases are genetic and occur in younger adults; 90 percent of Parkinson's cases have no known cause, and develop when people are in their 60s.

Symptoms like trembling, stiffness, slowness of movement and loss of balance and coordination begin gradually. Medications can help delay the onset. But doctors say in high-functioning people, the symptoms can be much more noticeable sooner.

"You're slow in multi-tasking, you cannot do things as fast, you cannot process information as fast. Your thinking slows down," said Harutunian.

Studies show major depression is present at any given time in 20 to 40 percent of Parkinson's patients. Dr. Harutunian says the key to helping newly diagnosed patients is to tell them what to expect to help them understand how the disease will progress.

But in people with a history of depression, a Parkinson's diagnosis can worsen the depression.

"Parkinson's can be a huge stressor, especially somebody who's battling depression, absolutely," said Harutunian.

But Dr. Harutunian says he has many patients diagnosed with Parkinson's disease who lead full, active lives many years after diagnosis.

"It's not curable, but definitely very manageable and treatable," said Harutunian.

The presence of a tremor is a classic early sign, but not all tremors indicate a person has Parkinson's.

One characteristic sign, though, is an involuntary movement that doctors call "pill-rolling." It looks like a person is rubbing their thumb and index finger together, as if there's a pill in between. It's found in about 70 percent of those with Parkinson's.

Early detection is key in managing Parkinson's disease.