Following the news that the late actor Robin Williams was in the early stages of Parkinson’s disease at the time of his death, the Michael J. Fox Foundation released a statement through its Foxfeed blog.

“Depression is a symptom of Parkinson’s disease, separate from the emotional response that comes with a diagnosis. As many as 50 percent of people with Parkinson’s show clinically significant symptoms of depression at some point in their disease course.

Depression in Parkinson’s may be due to the underlying changes in brain chemistry and circuitry from the disease itself. Evidence for this includes the fact that depression can predate a Parkinson’s diagnosis by a decade or more. More information is available on our Depression and Anxiety page.

The Michael J. Fox Foundation continues to pursue a single, urgent goal: the eradication of Parkinson’s disease. Explore our website for more information, connections to the Parkinson’s community, and resources for living with Parkinson’s disease.”

On late Thursday, Michael J. Fox, who was diagnosed with Parkinson's in the early 1990s and went public with it in 1998, tweeted "Stunned to learn Robin had PD. Pretty sure his support for our Fdn predated his diagnosis. A true friend; I wish him peace."

Williams had participated in the annual A Funny Thing Happened on The Way to Cure Parkinson's Gala, which raised nearly $5 million for Parkinson's research each year.

Click for more from the Michael J. Fox Foundation.