I've been a wow addict in the past and from my experience addiction is where you start losing your grip on reality and instead focus on an alternate one. During the time that I was immersed in wow, I would think about the game all day long even when I wasn't playing it and my thoughts were completely occupied with in-game details. Of course, I would get agitated when 'real life' interfered with my game time.

The way I see it, the people that are most weak to addiction either feel that real life is not stimulating enough, or they do not have the strength to confront real life head on. Both of those cases would lead a person to avoid reality and instead embrace a false reality where rewards easily accessible, situations are easier to control, and of course where stimuli are widely available. I would go as far as to say that this is the motivating factor for drug addiction as well. Of course repeated exposure and physical dependence worsens the situation, but having the mentality of 'turning off' real life primes a person to be more susceptible to addiction.

I don't mean to generalize what I'm saying to all addicts or all gamers because after all I'm pulling all of this out of my ass without any scientific backing but instead from self-introspection. I just wanted to share this because only when I realized that I needed to regain my grip on reality and figure out why I couldn't shake off my addiction, I was only then able to address the problem directly. I still game and smoke weed occasionally, but I try to keep myself firmly grounded and see things for what they really are.