Thesaurus:insane

• insane

• apeshit

• bananas

• barking

• barking mad

• barmy

• batcrap (vulgar)

• batpoop

• bats

• batshit (vulgar)

• batty

• bonkers

• bread baskets (British)

• cook    [WS]

• cracked

• crackers

• cray (slang)

• cray-cray (slang)

• crazed

• crazy

• cuckoo

• daft

• demented

• doolally (British)

• dotty

• eccentric    [WS]

• fruit loops

• fucked up (vulgar)

• gaga

• hatstand

• harebrained

• kooky

• loony

• loony tunes

• loopy

• lunatic

• mad

• mental

• mentally disturbed

• mentally ill

• meshigener (Polari)

• meshugge

• non compos mentis

• nucking futs (slang, humorous, mildy offensive, euphemistic)

• nutballs

• nuts

• nutso

• nutty

• potty

• psycho

• psychoceramic

• psychotic

• ripshit (vulgar)

• screwy

• squirrelly

• starkers

• unbalanced

• wackadoodle

• weird

• whacko

• wode

• yampy (British)

• a half bubble off plumb

• away with the fairies

• cuckoo for Cocoa Puffs

• doesn't have both oars in the water

• losing one's marbles

• nobody home (often accompanied with the gesture of a finger tapping a head)

• no longer in possession of one's faculties

• not all there

• not playing with a full deck

• not running on all cylinders

• not right in the head

• off one's box (British)

• off one's chump

• off one's head (British)

• off one's nut (British)

• off one's rocker

• off one's tree

• off one's trolley (British)

• off the deep end

• off the planet (Australia)

• out of one's box

• out of one's gourd

• out of one's head

• out of one's mind

• out of one's skull

• out of one's tree

• out there

• round the bend

• round the twist

• stark raving mad

• stark staring mad

• stark staring bonkers

• the cheese slid off one's cracker

• a few fries short of a Happy Meal

• touched in the head

• wired wrong

• mad as a hatter

• mad as a March hare

• nutty as a fruit cake

• sane    [WS]

• sober    [WS]