Investigation reveals no alcohol or illegal drugs in Robin Williams ' body . Actor and singer died August 11 at age 63 . Williams was diagnosed with depression , anxiety , early Alzheimer 's , widow says . Beloved Robin was buried deeply after death .
Autopsy reveals no alcohol or illegal drugs in Robin Williams ' suicide . Actor and comedian died August 11 at age 63 . Williams was struggling with depression , anxiety , early Parkinson 's , widow says . Beloved performer was mourned deeply after death .