Green’s Dictionary of Slang

(orig. US) an eccentric, a mad person.

1947		B. Schulberg Harder They Fall (1971) 160: Without Miki and Irving I would have been a shizo for sure.
1957		R. Prather Always Leave ’Em Dying 98: You’re a schizo, and real gone. Big menace, Scott.
1967		L. Bruce Essential Lenny Bruce 296: Pills are the answer: cured syphilis, it’ll cure schizos.
1972		T. Stoppard Jumpers Act I: His line is psychotics ... manic depressives – schizos.
1978		R. Price Ladies’ Man (1985) 221: I was acting like a street schizo. I was a street schizo. That was the act of a street schizo.
1981		S. King Roadwork in Bachman Books (1995) 366: That’s right you fucking schizo!
1995		J. Cameron Vinnie Got Blown Away 70: Then it’s down F wing Brixton, in with the schizos.
2009		J. Stahl Pain Killers 10: His psych eval describes him as a borderline schizophrenic [...] Who’s gonna believe a schizo in jail.
2012		J. Fagan Panopticon (2013) 120: She wants me to meet the old schizo [...] who supposedly saw bio-mum when she got committed.