Yeah, I wouldn't say that completing the primary progression curve over the course of 60 - 100 hours "Gamer ADD." You played the game long enough to reach a comfortable endpoint -- there's no shame in deciding that large player raids, which are often not part of that initial game play loop, aren't of interest to you. That's how I play MMOs, anyhow. I had lots of fun going through a couple of the character stories in The Old Republic
with a friend, but once the plot ended, we considered the game complete and moved on.
I'd define Gamer ADD as giving up games you're currently enjoying to buy other games you might also enjoy. Everyone does this to some extent, but return to the ones we really like later on. I'm thinking of the people who dont; I bet everyone on this forum has a friend who consistently gets a couple hours into a game, raves about it, but never finishes before the new hotness comes out.
Anyway, I've never pursued the endgame in MMOs because there are simply too many other great games I'd like to experience. Nothing holds your interest forever.