http://www.twitchguru.com/2006/08/08/world_of_warcraft_players_addicted/ A Harvard professor and clinical psychologist who doesn't quite grasp the problem with addictive nature or, more likely, understands it very well but refuses to present the issue clearly and honestly to the public. The result is the same, people will look at this and say, "Well there you go, pscyhology is a crock."
Are video games addictive (can they be)? Well yes, they can be and certainly are to some people. Do you fault the games? No, not at all. Many, many things have addictive potential. ANYTHING that allows the individual to escape from stressors (effectively escaping from the "real world") has the potential to be addictive. What the key issue seems to be, in my opinion, is how people cope with stress. If someone always engages in "escape behaviors" when confronted with stressors, then they will likely develop addictive behaviors. As stressors increase, they engage more heavily into the behavior and eventually the behavior itself creates the stressors from which they need to escape. To that end, here's a short list of things I think can be addictive but are not inherently unhealthy: movies, video games, music, books, exercise, food and sex. Combine those however you want, but the main thing is they all allow the individual to engage them and receive at least a temporary reprieve from stress. When an individual actively seeks them out more heavily correlated with stress levels, then a problem is likely to develop. End of story.
Should there be warning labels on games? Sure, if you're going to put warning labels on everything else too. I think anyone reasonable would balk at the idea of putting warning labels on all food advising that they could be addictive (though smart marketers would leap at the opportunity). What is needed is more public awareness of addictive behaviors, not warnings to alleviate responsibility from the individual.