one brick short of a full load
psycho
non compos mentis
insaniac
touched
fey
lunatical
loony tunes
insane in the membrane
maniacal
bodge
lunatically
insanely
not wise
demented
lunately
mad as a fish
few cards shy of a full deck
off one's rocker
off the beam
loco
gone fishing
nutzoid
off one's onion
mad
semihysterical
jimjam
reality challenged
balmily
gelt
bughouse
wackily
go mad
gobsmacked
cracked as an egg
nuttily
nutso
dottily
off one's chump
daftly
mooner
Ophelian
hatstand
crackers
crow
deranged
nutballs
half-crazed
insane
crazed
cuckoo for Cocoa Puffs
off-minded
cuckoo
insanity
unglued
idiomatical
lima bean
off one's head
stark staring mad
out of one's mind
maddening
noisomely
cooked
half-cracked
crazy
go potty
lunatic
potty
lose one's mind
mind-numbingly
loopy
off the rails
mad as a March hare
loony
insano
crazo
jumbled
higgledy-piggledy
disorderly
topsy-turvy
maniacally
hugger-mugger
hystericize
over the river and through the woods
rocket
crack up
gibbering
unrehearsable
stunod
mentalist
barren
bejeebers
sick-ass
junk
garbage