I was once so addicted to an online game (A mud...it didn't even have graphics...but was a text based MMO) that I spent on average 17 1/2 hours a day over an entire year. I once played for over a week without sleep because I was sick.
I did at least always drink and eat...but I was at home so that didn't stop me from playing.
Online games are deadly addictive because there is always something to shoot for. There is always a way you can improve yourself and a goal that you can achieve. In addition they have non-stop competition and the worst ones cause players to "race" to be the best.
I was the highest player in a guild (like a class) in the game I played and was shooting for a goal that seemed impossible and had never been done. This caused me to have constant motivation and rewards for accomplishing things so I had endless enjoyment. Every single hour I played that game I was interested, motivated and drawn in.
I had already been playing alot before that year and slowly drew away from my friends (As you can guess I didn't do ANYTHING with them or anyone else for that year) and by that time I had ceased to consider anything outside of the game important. I had saved enough money to pay the bills and buy food/drink and that was it.
I was very lucky to be only 24 at the time with a very fast matabolism so I didn't gain much weight at all (first time I ever gained about 20 pounds in fact)....and over all had no real long term negative effects from my crazy gaming bing.
But games like that can totally take over your life...and you don't have to live in China for it to happen. I'm even fairly good looking, had friends, and a fairly good life...the gaming was just non-stop fun. I would get bored easily (Always used to carry a book around with me in case I had to wait for something) and that is what killed me. I NEVER got bored playing my game. Why try and figure out what new thing your gonna do with friends on the weekend (burning man, rock climbing, white water rafting, magic the gathering etc etc) when you have something you can do that is fun ALL THE TIME.
I still play games (DDO online right now) but never like I did back then. Rarely spend more then 20 hours a week all together playing games and often half that. Honestly though.......I don't think I've ever had as much non-stop fun as I did that year. It was very hard when I accomplished my goal and didn't really have anything left to shoot for. I stopped playing cold turkey pretty soon after that....and due to extreme boredom ended up dating and meeting my current wife (over 10 years) within 6 months.
Online games can be very addicting.
congratulations.