How much other screen time does he get? I wold limit to 2 hours of screen time a day max, including TV, video games, and computer. There is a fair bit of evidence that more than that can negatively affect weight, grades, sleep, emotional state, social life, you name it.
I sometimes wonder if video games can promote shorter attention spans and like ADD.
There is some evidence that they do, but it's also a little shaky. The effect sizes are small, and it's hard to separate it all out. There's also some evidence that violent games can desensitize kids to violence, BUT not all kids...it's complex.
