His publicist, Mara Buxbaum, commented that Williams had
severe depression before his death.
[152] His wife, Susan Schneider, said that in the period before his death, Williams had been sober but was diagnosed with early-stage
Parkinson's disease, which was information that he was "not yet ready to share publicly".
[153][154] An autopsy revealed that Williams had diffuse
Lewy bodies (which had been misdiagnosed as Parkinson's), and this may have contributed to his depression.
[155][156][157]
In an essay published in the journal
Neurology two years after his death, Schneider revealed that the pathology of Lewy body disease in Williams was described by several doctors as among the worst pathologies they had seen. She described the early symptoms of his disease as beginning in October 2013. Williams's initial condition included a sudden and prolonged spike in
fear,
anxiety,
stress and
insomnia, which worsened in severity and included
memory loss,
paranoia and
delusions. According to Schneider, "Robin was losing his mind and he was aware of it ... He kept saying, 'I just want to reboot my brain.'"
[158]
Williams was found dead at age 63 in his home in
Paradise Cay, California, on August 11, 2014.
[10][159] The final autopsy report, released that November, concluded that Williams's death was a suicide resulting from "
asphyxia due to hanging".
[160] Neither alcohol nor illegal drugs were involved, and prescription drugs present in his body were at therapeutic levels. The report also noted that Williams had depression and anxiety.
[161][162] An examination of his brain tissue suggested that Williams had "diffuse Lewy body dementia".
[156] Describing the disease as "the terrorist inside my husband's brain", his widow Susan Schneider Williams said that "however you look at it—the presence of Lewy bodies took his life", referring to his previous diagnosis of Parkinson's.
[158] She noted "how we as a culture don't have the vocabulary to discuss brain disease in the way we do about depression. Depression is a symptom of LBD and it's not about psychology – it's rooted in neurology. His brain was falling apart."
[163] Medical experts struggled to determine a cause, and eventually diagnosed him with Parkinson's disease.
[158]
The
Lewy Body Dementia Association (LBDA) clarified the distinction between the term used in the autopsy report, "diffuse Lewy body dementia", which is more commonly called "diffuse Lewy body disease", and refers to the underlying disease process—and the umbrella term, "
Lewy body dementia"—which encompasses both
Parkinson's disease dementia (PD) and
dementia with Lewy bodies (DLB).
[12] According to LBDA spokesperson Dennis Dickson, "The report confirms he experienced depression, anxiety, and paranoia, which may occur in either Parkinson's disease or dementia with Lewy bodies. ... In early PD, Lewy bodies are generally limited in distribution, but in DLB, the Lewy bodies are spread widely throughout the brain, as was the case with Robin Williams."
[12] Ian G. McKeith, professor and researcher of Lewy body dementias, commented that Williams's symptoms and autopsy findings were explained by DLB.
[13]