According to E! Online, "They found that the beloved actor and comic legend passed from asphyxia due to hanging in the manner of suicide. An extensive toxicology evaluation revealed an absence of both alcohol and illicit drugs in Williams' system at the time of death."
The report also states that Williams had prescription medications in his system, which were limited to "therapeutic concentrations."
The findings are consistent with a statement Williams' wife, Susan Schneider, released after 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. 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."
Echoing that sentiment, Williams' daughter, Zelda, has used social media to stress the importance of reducing the stigma of mental illness and depression. "My dad openly fought depression his whole life, both in general and his own. No matter what anyone says, it is a FIGHT. Fight on," she tweeted on World Mental Health Day. (E! Online)