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