Slate recently published a piece about Don's obvious alcoholism that got tongues wagging. After all, what came off as a retro gimmick in Mad Men's earlier season ("Oh, they're drinking booze at the office. In the morning. During business meetings. Why can't my office be cool like that?") has turned into something far more sinister. Now, it would appear that Don is just a few drinks away from completely losing it.
Jon Hamm does a great job in bringing pathos and realism to Don's downward spiral; however, other actors have been less convincing in their portrayals of addicts in denial.