I'm not sure, but I think that one has been disproven: http://news.wisc.edu/study-finds-violent-video-games-provide-quick-stress-relief-but-at-a-price/

The playing of games is a great mood elevator, but the violence part can make us perceive the world as more hostile.

Plus, using different violence as a way to mitigate anger actually serves to prime us for more anger. https://www.psychologytoday.com/blog/ulterior-motives/200909/you-cant-punch-your-way-out-anger

So play can relive stress and curb aggression, but violence only begets more violence it seems. Fascinating topic, but I do find I like my media violence cartoony and ridiculous rather than realistic and visceral as it feels a bit different to me.