Bush on Steroids?

Of course this seems ridiculous. (See Bruce Reed, The Has-Been: The Cream and the Clear). But it might explain his neurological symptoms:
1. He's less articulate than he was when he ran against Ann Richards.
2. He falls over a lot.
3. 2 or 3 hours of exercise per day is obsessive. He's trying to stay off the booze, but is there something more?