batty
up the wall
cracky
bananas
nut-bar
fruity
siao
kee siao
three stops short of Dagenham
toppy
daft
doolally tap
bugfuck
bonkers
berko
nuts
funny in the head
bats
gila
off one's dot
distraught
one fry short of a Happy Meal
mad as a box of frogs
crazy as a bedbug
meshugge
round the bend
flip out
flip
doolally
nutty
wud
round the twist
plumb crazy
madden
lunatic
off one's head
becrazed
mad as a March hare
out of one's mind
hatstand
unglued
bughouse
crackers
off one's chump
nutso
off one's trolley
meshuggener
not right in the head
cuckoo for Cocoa Puffs
daffy