mad as a box of frogs
crazy as a bedbug
nuts
daft
nut-bar
siao
fruity
kee siao
up the wall
cracky
bats
batty
three stops short of Dagenham
plumb crazy
toppy
bonkers
bananas
off one's dot
funny in the head
distraught
crazy as a cootie
crazy as a cootie bug
stark raving mad
becrazed
cracked as an egg
unglued
out of one's mind
off one's head
off the beam
nutzoid
off one's onion
off one's rocker
doolally tap
gone fishing
insane in the membrane
loony tunes
barking mad
berko
bugfuck
gila
one fry short of a Happy Meal
off one's chump
lunatic
crackers
hatstand
nutso
bughouse
nutty
gobaloon
nutballs