hatstand
bughouse
lunatically
bananas
semimadness
off one's chump
nutso
three stops short of Dagenham
toppy
get one's freak on
crazy as a cootie bug
out of one's mind
wackadoo
off one's head
crazy as a cootie
crazy as a pet coon
whacked-out
few cards shy of a full deck
nutcake
mad as a hatter
mad as a mongoose
insaniac
crazily
unglued
becraze
lose one's mind
gobaloon
muddleheadedness
psycho
insanity
craziness
screwy
hysterization
spack attack
crazy as a shithouse rat
bugs
doolally
nut-bar
touched
cooked
apartments to let
Ophelian
fey
crazedly
phrenesis
funny in the head
mad person
loopy