Is it like the adept power, +1 to physical stats, -1 to mental stats? Or is it something different?

as i see it, Either you get nothing.. except unability to stop fighting, or you get a bonus aswell (if you go by Street magic, it just says.. might) Which eventually lead to.. GM's decision

You run berserk for 3-(wil+cha hits) rounds (injury mods apply). While berserk, you attack the next lifeform without regards for your safety. You can avoid the effect completely with 3 hits. No attribute mods.