Robin Williams had Lewy Body Disease

Robin Williams

The official cause of Robin Williams' death, released Friday by the Marin County coroner, was ruled a suicide by hanging, with no evidence of alcohol or illegal drugs in his system and only therapeutic concentrations of prescribed medications.

Williams had long battled alcoholism, drug addiction and depression, but in November 2013 he was diagnosed with Parkinson's disease, according to his widow, after noticing a tremor in his left arm and difficulty moving on his left side as early as 2011.

Now a redacted pathology report from the autopsy on Williams' body has been made public and mentions "Diffuse Lewy body dementia,". Given that Dementia with Lewy Bodies can involve vivid visual hallucinations, it has now been speculated that perhaps such hallucinations may have lead to Williams' death.

Media reports, quoting anonymous "family sources," state that Williams' family believes that Lewy body disease was a critical "triggering" factor in his suicide. If so, this would be an unusual manifestation of the disease. Suicides have not been linked specifically to the hallucinations of Lewy Body Disease in the past.

Dennis Dickson, MD

"The use of the term dementia in the neuropathology report should not be inferred to mean that dementia was observed during life," warns Dennis Dickson of the Mayo Clinic in Jacksonville, who says he reviewed the neuropathology report.

"Mr. Williams was given a clinical diagnosis of (Parkinson's) and treated for motor symptoms. The report confirms he experienced depression, anxiety and paranoia, which may occur in either Parkinson's disease or dementia with Lewy bodies," Dickson said.