Great topic. The term "functional alcoholic" (or even "high functioning alcoholic") seems a bit problematic. Does this mean, one can wake up, go to work, perform his/her roles & responsibilities at work & then go home? I guess it meets some criteria of the definition for being "functional." However, in order to be a whole human being, there is more to life than merely functioning in one area of one's life. (This doesn't pertain to just addicts).
I like the reframing of the "functional A" as a stage, not a type.