Susan Schneider, the wife of deceased actor Robin Williams, has said that the late comedian was struggling with the early stages of Parkinson's disease at the time of his death.

"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," she revealed on Thursday.

Susan made the statement after it emerged in the media that the actor, who was once addicted to drug and alcohol, may have fallen off the wagon.

"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," she wrote in a statement.

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

Williams was last seen alive on Sunday at his home at about 10 p.m by his wife. An emergency call was placed to the Sheriff's Department on Monday noon by someone from the actor's house in the San Francisco, California.

On Thursday, the Marin County coroner revealed that Williams committed suicide by hanging himself with a belt. The coroner added that Williams also had cuts on his wrist at the time of his death.

A representative for Williams said in a statement the 63-year-old actor had been battling "severe depression of late."