bats
distraught
off one's dot
kee siao
fruity
siao
nuts
nut-bar
bonkers
three stops short of Dagenham
toppy
bugfuck
berko
crazy as a bedbug
cracky
up the wall
batty
funny in the head
wud
round the twist
daft
mad as a box of frogs
gila
one fry short of a Happy Meal
unglued
bananas
flip
off one's trolley
not right in the head
meshuggener
doolally tap
flip out
gobaloon
crackers
bughouse
off one's chump
hatstand
nutso
madden
off one's head
out of one's mind
nutzoid
off one's onion
insane in the membrane
gone fishing
nutty
off one's rocker
off the beam
loony tunes
not wise