nutty as fruitcake

insane kooky mad nuts nutty silly wacky

ape berserk cuckoo lunatic potty psycho screwball

barmy bats in the belfry batty bonkers cracked crazed daft delirious demented deranged dingy dippy erratic flaky flipped flipped-out freaked-out fruity idiotic mad as a March hare mad as a hatter maniacal mental moonstruck of unsound mind out of one's mind out of one's tree out to lunch round the bend screw loose screwy touched unbalanced unglued unhinged unzipped

balanced calm collected rational reasonable sane sound

realistic responsible sensible