C.A.
I don't have any advice, but a little story I guess. My cousins oldest son, now 13 was addicted to video games. He would play whenever he could, starting at about 3 or 4. He was so mean to his brothers and his punishment would be to have them taken away. He would be nice as could be (and I don't think it was to get what he wanted) and within minutes of playing the games he would be mean again. So mean you could see it in his eyes. He did eventually out grown this, about 8 years later. His younger brother played almost as often, but the games didn't have the same effect on him.
Another down side was taking her older one anywhere. He hated being out, socializing, being outside in generally. My mom watched all 3 of my cousins sons one summer and it got to the point she would leave the oldest one home with someone else when they went some where because he made everyone else so miserable.
Do with this what you'd like, you story just sounds a little familiar to me.
Best of luck,
C.