Robin Williams Robin Williams

The death of Robin Williams, who hung himself in August, was allegedly triggered by Lewy Body Dementia (LBD), TMZ reports.

According to documents obtained by the website and sources close to the actor's family, Williams struggled with the disease, which is the second most common type of progressive dementia after Alzheimer's. In LBD, protein deposits develop in nerve cells in the brain, causing visual hallucinations, fluctuations in alertness and result in rigid muscles and tremors, much like in Parkinson's disease, which Williams' wife, Susan, revealed he was recently diagnosed with after his death.

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Susan reportedly told authorities that Williams had been complaining about the medications he was on to treat the disease. According to TMZ's sources, LBD was the "key factor" in his suicide and that his doctor's agree.

Williams' family revealed after his death that he had been suffering from anxiety and depression as well.