Robin Williams died by suicide on August 11, 2014, at his home in Paradise Cay, California. The cause of death was asphyxia due to hanging, confirmed by the autopsy report

. He used a belt wrapped around a door handle to hang himself

. In addition to his long history of depression and anxiety, Williams had recently been diagnosed with Parkinson's disease. However, after his death, an autopsy revealed that he was actually suffering from diffuse Lewy body dementia (DLB), a brain disease that affects cognition, movement, and mental health. This disease likely contributed significantly to his symptoms of paranoia, hallucinations, anxiety, and personality changes, which had worsened in the last year of his life

. Toxicology reports showed that Williams had antidepressants, caffeine, and levodopa (used for Parkinson's) in his system at therapeutic levels, indicating he did not overdose intentionally

. His wife, Susan Schneider Williams, described Lewy body dementia as "the terrorist inside my husband's brain," emphasizing that the neurological disease was a key factor in his death, beyond just depression

. In summary, Robin Williams died by suicide through hanging, with underlying severe depression complicated by undiagnosed Lewy body dementia, which had caused significant neurological and psychiatric symptoms