I have reinserted mention of Watts' drinking, and here is my reasoning:  According to the article revision history, the original mention of his potential alcoholism specifically stated that alcoholism contributed to his death.  That statement was removed by an anonymous user on 06:49, 8 November 2011‎ as being speculative, and that removal seems appropriate given that the source (Furlong biography) does not state any medical opinion of his death being related to alcohol.  However, Furlong does describe in detail in several places in the book that his friends and family were concerned over his drinking, so that is how I've described it in my edit.  If reference to his drinking is to be removed, then an argument must be made that it is not relevant to the wiki article.  The argument cannot be based on lack of citation, given that this same source is used throughout this wiki article.  It's not fair to refute only one part of a source, unless the refutation comes from a different source.  And in that latter case, the article should state that sources disagree on this point.