Is video game influence a defense to rape and if a teenager is addicted to video game (like grand theft), can that be used on his defense?

No.

No. Insanity could be a defense but then you get locked up in a insane asylum rather than a prison.

First of all, Grand Theft Auto deals with stealing cars and has nothing to do with rape that I know of. Second of all, the answer is no and rightfully so. I would hate to think that people could commit heinous, violent acts against people and be able to shirk responsibility for those actions by saying it was a video game's fault.

If you raped a woman you will not be able to use your addiction to video games as a defense. Rape is a violent felony offense, and I have no doubt that most video games are violent in nature, but they are not the reason why young men commit suicide, go Postal, or rape a woman. That is due to their anti-social personality, lack of morals, and bad decision making, If you are insane you may be able to use that as a defense to a crime, but only f you thought you were having sex with a watermelon or a woman from outer space that was about to kill you, since that is their definition of legal insanity. That you thought you were stabbing a watermelon and not a person because you did not know right from wrong or the nature of your actions. Very few people qualify foe such defenses and juries do not like to let someone off a serious crime just because they may suffer from a disease or an addiction. People must take responsibility for their actions and hope that they learn from their mistakes and not repeat them. If it is statutory rape you may only get a short jail sentence, but a rape case could be 10-25 years, especially if the woman was injured or a weapon was used. The worst part is, they don't have video games in prison so you will have to go cold turkey or maybe do crossword puzzles or suzoku.

That is a far stretch. I doubt that it would work, but the life circumstances of the teen would be taken into consideration upon sentencing, and this could be a mitigating factor if stated correctly along with a psychological evaluation.