Robin Williams Battled Dementia Before His Suicide

Robin Williams' widow, Susan Schneider Williams, revealed a dark motive for the beloved actor's suicide in August 2014.

In the journal Neurology, Schneider Williams penned an essay about her husband's struggle with Lewy body disease, which she said delivered an "intense, confusing, and relatively swift persecution" to the actor. The disease is a form of dementia that causes a decline in cognitive abilities (memory, language, thought) due to degeneration of the brain, per the Lewy Body Journal.

Schneider Williams wrote that the famed comedian had trouble remembering lines during the filming of Night at the Museum 3 in the spring of 2014, explaining that the "loss of memory and inability to control his anxiety was devastating to him." Schneider Williams claims he struggled with paranoia and delusions, as well as depression, stemming from the brain disease, which can only be diagnosed after death.

"He had been struggling with symptoms that seemed unrelated: constipation, urinary difficulty, heartburn, sleeplessness and insomnia, and a poor sense of smell—and lots of stress," she wrote. "All four of the doctors I met with afterwards and who had reviewed his records indicated his was one of the worst pathologies they had seen. He had about 40 percent loss of dopamine neurons and almost no neurons were free of Lewy bodies throughout the entire brain and brainstem."

Schneider Williams said her husband knew there was something wrong, but no one realized what was causing his mental and physical problems was connected. Even if doctors eventually reached a correct diagnosis, Schneider Williams said, it would likely have come too late. "If Robin was lucky, he would've had maybe three years left," she told Good Morning America in November 2015. "They would've been hard years. The disease is like a sea monster with 50 tentacles of symptoms that show when they want," she said. "It's chemical warfare in the brain, and we can't find it until someone dies, definitively. There's no cure."