Conversation so far:
What illness did Eugene O'Neill have?
After suffering from multiple health problems (including depression and alcoholism) over many years, O'Neill ultimately faced a severe Parkinsons-like tremor.
When did he die?
O'Neill died in Room 401 of the Sheraton Hotel (now Boston University's Shelton Hall) on Bay State Road in Boston, on November 27, 1953, at the age of 65.
Are there any other interesting aspects about this article?
Parkinsons-like tremor in his hands which made it impossible for him to write during the last 10 years of his life; he had tried using dictation.
When was the last time he wrote?
He managed to complete Moon for the Misbegotten in 1943, just before leaving Tao House and losing his ability to write.
Who was there when he died?
Dr.
Harry Kozol, the lead prosecuting expert of the Patty Hearst trial, treated O'Neill during these last years of illness.
He also was present for O'Neill's death.

Question: Did he have any other illness?
Self-contained rewrite: Besides Parkinsons, did Eugene O'Neill have any other illness?