opposite word of sane:

insane, amuck, amok, berserk, demoniac, demoniacal, possessed(predicate), balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kooky, kookie, loco, loony, loopy, nuts, nutty, round the bend, around the bend, wac