not have both oars in the water
becraze
go ham
lose one's mind
go potty
dumb out
get one's freak on
crazen
go mad
flip
hellify
take leave of one's senses
jimjam
have bats in one's belfry
half-cracked
loco
tripping
flip shit
lose it
go bananas
not right in the head
meshuggener
craziness
nerts
bananapants
go moggy
gone fishing
insane in the membrane
loony tunes
nutzoid
off one's rocker
off the beam
off one's onion
madden
drive someone crazy
tonto
5150
cooked
bananas
mooner
apartments to let
gelt
junkiness
gobaloon
crazy-ass
hatstand
mental case
cuckoo
lunatical
cuckoo for Cocoa Puffs