Wrong. It's mentally addictive. Just like alcohol.
EDIT: Apparently there's a rehab clinic for video gaming (or internet, I can't remember which) in the Netherlands somewhere. Sorry I can't cite the source. I read it ages ago.

I heard about that too, good idea really.

Just like WoW too it seems.
I wouldn't class gaming to such an extreme an addiction tbh, more like a phase. I think if you ask around alot of people have spent stupid amounts of time (staying up all night playing), over long durations eventually you just get bored with it and stop playing to such an extreme, that's something that will probably never happen with a drug. To say games can control you're life just doesn't sit right with me, they're just a past time of which you are in total control. Tbh, I just can't understand the mentality that would lead someone to believe that they are addicted to a game. Wonders never cease.
Some have said it's the initial fun-factor. You play a game, have fun, then obviously you're gonna go back to it. That's why to me a lot of PS2 and 360 games I have just... sorta begin to collect dust, because they're fun at first, but like you said, they get boring. Games like SOTC and GH, I can never put down because of how much fun they are.
It was the same with WoW at first, I loved the huge environments, the fighting was dull at first, but new abilities and skills made it interesting, likewise with party-instances etc. Then it became more of a superiority thing, where you hold a grudge against the other faction and begin to show "just how big your e-pen0r" is to them.
Eventually though, you see the light and realise how pointless it is, or rather you just stop having fun with the game.
I'd defo say the fun-factor is what triggers an addiction, but that's pretty much obvious... Hrm... Forget anything I just said. xD