my other son, when told he would be limited in his xbox play time, got very aggressive and took the xbox system and ran out of the house with it.
It becomes their comfortability factor and gives them a sense of false reality and almost an addiction.
They become conditioned to violence with some games..
Take away a toy of any type from most young people, mentally ill or not, and you will get a negative reaction.
Becoming conditioned to violence due to the content of the games I say is unrealistic as even my mentally ill brother could understand the difference between a video game and reality.
But, again, different people can react to stimuli in different ways. Allowing my brother to watch a movie like Natural Born Killers would be a very bad thing, and we knew better.