Robin Williams was battling the early stages of Parkinson's Disease at the time of his death, his wife has said.
In a statement to the media on Thursday, Susan Schneider said her husband's sobriety was "in tact" but he had been diagnosed with the degenerative disease, though he had not made that public.
Here's Schneider's full statement:
"Robin spent so much of his life helping others. Whether he was entertaining millions on stage, film or television, our troops on the frontlines, or comforting a sick child - Robin wanted us to laugh and to feel less afraid."
"Since his passing, all of us who loved Robin have found some solace in the tremendous outpouring of affection and admiration for him from the millions of people whose lives he touched. His greatest legacy, besides his three children, is the joy and happiness he offered to others, particularly to those fighting personal battles."
"Robin's sobriety was intact and he was brave as he struggled with his own battles of depression, anxiety as well as early stages of Parkinson's Disease, which he was not yet ready to share publicly."
It is our hope in the wake of Robin's tragic passing, that others will find the strength to seek the care and support they need to treat whatever battles they are facing so they may feel less afraid."
Parkinson's gradually affects the nervous system. It causes tremors and stiffness in the bodies of sufferers, as well as difficulties moving.