MARIN COUNTY (CBSLA.com) — There was no evidence of alcohol or illegal drugs in Robin Williams’ system when he committed suicide at his Northern California home, according to autopsy results released Friday.

The autopsy for the 63-year-old stated he had taken prescription medications but only in “therapeutic concentrations.”

READ MORE: Día De Los Muertos Celebrations and Others Return To LA

His death was officially ruled a suicide that resulted from asphyxia due to hanging.

PHOTOS: 2014 CELEBRITY DEATHS

READ MORE: Sigma Nu Fraternity At USC Suspends Member At Center Of Sexual Assault Allegations

The Oscar-winning actor was found unconscious on the morning of Aug. 11 in the bedroom of his home in Tiburon in the San Francisco Bay area, according to officials.

In a statement released a few days after his death, Williams’ wife Susan Schneider said he “was not yet ready to share publicly” that he was in the early stages of Parkinson’s Disease and that his sobriety was “intact” despite battles with depression and anxiety.

Throughout his career, Williams was nominated for three Academy Awards and won the best supporting actor Oscar for his role in “Good Will Hunting”. He also won four Golden Globes, for “Mork & Mindy,” “Good Morning, Vietnam,” “Mrs. Doubtfire” and “The Fisher King,” in addition to two Emmy Awards, two Screen Actors Guild awards and five Grammys.

MORE NEWS: USC Places Sigma Nu Fraternity On Interim Suspension After Reports Of 'Possible Drug-Facilitated Sexual Assaults,' Students Protest In Support Of Victims

[display-posts tag=”Robin-Williams” wrapper=”ul” posts_per_page=”4″]