Green’s Dictionary of Slang

of a person, eccentric, insane, disorientated, esp. when demonstrating two extreme forms of behaviour.

1957		M. Gair Sapphires on Wednesday 120: I think he must have a split mind—be schizo or something [OED].
1960		G. Swarthout Where the Boys Are 35: It sounds like something out of 1984! And you know it and that’s why you’re so schizoid!
1961		Kerouac letter 10 June in Charters II (1999) 294: I had a ball that summer time, but overdid it & went a little schizo.
1969		N. Cohn Awopbop. (1970) 232: Schizo eyes staring out into nothing.
1977		J. Sayles Union Dues (1978) 279: Did he ever recognize the fact, be wise to himself, and go on with it just the same? Schizo City if that was the case, with Africa, America and Phillips Exeter all pulling in different directions.
1978		Ramis, Kenney & Miller Animal House [film script] I won’t go schizo, will I?
1989		P. Munro Sl. U.
1999		K. Sampson Powder 109: What could’ve changed so drastically during the course of one short evening? [...] Nothing. She was schizo.
2001		(con. 1981) A. Wheatle East of Acre Lane 239: Oh my God, he’s gonna go schizo.
2001		Guardian 12 Mar. 5: Only one third thought it was unacceptable to call people ‘schizo’ or ‘psycho’.
2012		J. Fagan Panopticon (2013) 241: He’s so schizo, it’s hopeless.
2014		M.E. Fitch ‘Tommy, Who Loved to laugh’ in ThugLit Sept. [ebook] [T]esting his temperament in the hopes that the kitchen wouldn’t catch the brunt of his schizo rage.
2016		Mavado ‘Big Bumpa Gal’ 🎵 Me fuck you till you schizo.