I was addicted to Morrowind when I first played it in 2005. Family dragged me on vacation for a week that summer and it was hell. Now TES game since has done that to me. I've always been able to get up and do other things without having the craving. I don't think it's because they're less good than Morrowind; I think it was just my state of mind that year and the fact I'd never had a TES game to play before.

addictive in gaming means the need to go back, not the withdrawl effect.
you can't stop playing, hours go by very very fast, you neglect different responsabilities of real world and close yourself in the game.
for real it grabs your soul, because it doesn't let you do other stuff you might like to do.
event for an artist, painter type person, or who does stuff with his hands, if skyrim catches on, there is a problem for the other activities

base config: sleep-work-skyrim
optional: spouse / partner - maybe friends (if they don't play skyrim that's really bad)
very optional: chores & responsabilities
lost way down the list: other ideas

zhagsten is right on the spot.
some gamers play for fun, and if the activity doesn't cripple the capacity to do other stuff is just that, fun.
but if it takes over their time entirely, there is un underlying problem. this is good because this is a visible simptom, that cand lead to a treatement. treatment is a vague term, that can be anything from just better comunication to serious medication due do some complex problems of the individuals.