I believe the main problem comes from not being able to find a good outlet for stress. Friends can help those addicted by getting them involved in outdoor activities but the irony is the friends of a gamer addict are usually also addicts to games.
Qiana has a good point. Games are meant to entertain and keep you happy so to speak but when its the only thing that can entertain you then its trouble. Serious addicts tend to be antisocial and let work or studies fall aside like junkies.
I had a buddy lose his job because he stopped showing up. Apparently he was addicted to WoW. He lost his job, car, and real life friends because of it. It seemed as if he forgot how to be social except through the medium of the internet. When I ran into him, he could barely make eye contact and seemed like he was in a rush - likely just to get home and get back online. Oddest thing I've ever seen, and I grew up with multiple drug/alcohol addicts in the family.
I don't know Chris, you can like something a lot without becoming addicted. Addiction is like saying it has some sort of control over you so you can't operate like you normally do. What you're describing sounds like you're very aware of when to switch it off, the addict isn't. Just wait til they bring out those hologram games in the future - there will be loads of addicts then.