go mental

freak out go off lose it

blow a gasket blow one's mind blow one's stack blow one's top crack up flip one's lid flip out fly off the handle go ballistic go bananas go batty go berserk go bonkers go buggy go cuckoo go daffy go haywire go kooky go loco go loony go nuts go nutty go off one's rocker go off the deep end go off the wall go psycho go wacko go wacky lose control of oneself lose one's cool lose one's mind wig out