What exactly counts as incapacitated

So our President is an alcoholic. No debate about that. However, claims he's been sober since his 40th birthday. However, rumors coming out of the Bush Administration as reported in the National Enquirer report that El Presidente de Douche Bag is back on the sauce. While I have serious doubts about whether this is true or not, it raises an interesting question. If the President becomes a full blown alcoholic again, can he legally be removed from power?

Well, a quick search of presidential succession shows that "The 20th and 25th Amendments establish procedures and requirements for the vice president to assume the duties and powers of the president if the president is permanently, or temporarily disabled" Can being a drunk count as being disabled? Any law students who read this should chime in, because this scares the shit out of me.