Apparently, from suicide.
I have to admit, I’ve never read any of Dr. Thompson’s books, but I have read some of his other writing in magazines and was suitably impressed. Also, it didn’t hurt that he was a good friend of Warren Zevon, who I admire greatly. Dr. Thompson, father of “gonzo journalism”, was the basis for another of my favorite characters, Doonesbury’s Uncle Duke. He was an icon of Americana that simply cannot be replaced.
This article at MSNBC.com has details, scant though they may be, regarding his death. No word on a suicide note, but his death was caused by an apparently self-inflicted gunshot wound to the head.
You may not agree with his politics or his journalistic style, but you cannot deny the profound influence he had on the publishing landscape of the 20th century. Good luck on the other side, Doc.