abnormal
bereft of reason
brainsick
catatoniac
certifiable case
crackbrained
cracked
crazed
crazy
creep
daft
deluded
demented
deprived of reason
deranged
disoriented
distraught
flighty
freak
hallucinated
insane
irrational
loco
loony
loose cannon
lunatic
mad
maddened
manic
manic-depressive
mazed
mental
mental case
mentally deficient
meshuggah
moon-struck
non compos
non compos mentis
not all there
not right
nutcase
odd
of unsound mind
off
paranoiac
paranoid
psychopath
psychopathic case
psychopathic personality
psychotic