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