Conversation so far:
What kind of illness did playwright Eugene O'Neillhave?
Eugene O'Neill faced a severe Parkinsons-like tremor in his hands.
How long did playwright Eugene O'Neill suffer from Parkinsons-like tremors?
The Parkinsons-like tremor in Eugene O'Neill's hands made it impossible for him to write during the last 10 years of his life.
Is Parkinson's Disease what killed playwright Eugene O'Neill?
The examination of Eugene O'Neill's brain clearly shows that he did not have Parkinson's disease.

Question: Was his death caused by health problems or suicide?
Self-contained rewrite: Was playwright Eugene O'Neill's death caused by health problems or suicide?