Williams, 63, died of suicide at his Tiburon, Calif., home, according to local police.
Susan Schneider released a statement Thursday revealing that as well as depression, her husband was also struggling with a Parkinson's diagnosis.
Below is her entire 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.”
Struggle with depression
Williams had been battling severe depression recently, said Mara Buxbaum, his press representative. Just last month, he announced he was returning to a 12-step treatment program he said he needed after 18 months of nonstop work. He had sought treatment in 2006 after a relapse following 20 years of sobriety.
He was last seen alive at home about 10 p.m. Sunday, according to the Marin County coroner's office. Shortly before noon, the Sheriff's Department received an emergency call from the home, where the star of Good Will Hunting, Mrs. Doubtfire, Good Morning, Vietnam and dozens of other films was pronounced dead.
Sheriff's officials said a preliminary investigation determined the cause of death was suicide due to asphyxia.
Schneider and Williams married in 2011.
Williams leaves behind three children: Zachary, 31; Zelda, 25 and Cody, 19.