Green’s Dictionary of Slang

buggy adj.2

also buggish
[bug n.4 (2d)]

(US) lit. or fig., unstable, insane.

[Aus]Bulletin (Sydney) 5 Nov. 12/4: ‘Permit me to add that if I am again stopped in the public street when on duty by such a mob I shall not be responsible for the consequences.’ Meek old buggy Christian!
[Aus]G. Boothby On the Wallaby 248: The most wretched old scarecrow of a buggy mortal man ever saw.
[US]H. Hapgood Autobiog. of a Thief 168: These latter would tell the keepers that he was buggy.
[US]M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 213: buggy, confused and simple. ‘He’s buggy, sure as you live.’.
Bessie Tucker ‘Bogy Man Blues’ 🎵 If your man get buggish and he wanna go / [...] let the fool man go.
[US]E. Anderson Hungry Men 176: I’m not half as buggy as some people think.
[US]W. Guthrie Seeds of Man (1995) 380: That there damn-derned Charlie has gone jest as buggy as a damn peach-orcherd boare hog.
[US]N. Algren Walk on the Wild Side 39: Crazy Old Hasteth! Little-Time-To-Repent! [...] Buggy old Just-As-I-Am.
[US]Mad mag. Dec. 48: The best way to drive a baby buggy is to tickle his feet!
[US]J. Thompson Pop. 1280 in Four Novels (1983) 484: Take your buggy boyfriend and clear out of here before I forget I’m a lady.
[US]T. O’Brien Going After Cacciato (1980) 141: My old man, he went buggy when he saw the mess.
[US]C. Hiaasen Sick Puppy 322: It might also have lowered Robert Clapley’s buggy anxiety to a saner level.

In compounds