Green’s Dictionary of Slang

1. (drugs) intoxicated by a drug.

1953		E. Hunter ‘Vicious Circle’ in Jungle Kids (1967) 34: I thought Turk was just hopped [...] I figured that Turk would never dream that up though, no matter how wigged he was.
1955		H. Braddy ‘Narcotic Argot Along the Mexican Border’ in AS XXX:2 88: WIGGED, adj. Said of an addict, with a muddled head.

2. inspired or intoxicated by an idea.

1955		Babs Gonzales ‘The Be-Bop Santa Claus’ 🎵 Pops was wigged behind this crazy scene.
1966		New Yorker 31 Dec. 28: He’s a hot-dog surfer and he used to be real wigged on Zen.

3. eccentric, insane, deluded, out of touch.

1960		‘Lord Buckley’ Hiparama of the Classics 20: Jammed with the Wigged out Cats and Kitties, Noble-Heads all ready for the Ball.
1971		E.E. Landy Underground Dict. (1972).
1977		(con. 1969) M. Herr Dispatches 235: There were more young, apolitically radical, wigged-out crazies running around Vietnam than anybody ever realized.
1985		Eble Campus Sl. Oct.
1991		Eble Campus Sl. Mar. 10: wigged – anxiety-ridden.
1999		J. Ridley Love Is a Racket 297: A dose of the wigged-out kooky shit that made up my life.
2002		S. Maloney Something Fishy (2006) 222: Jesus [...] He’s wigged out, gone Lady Macbeth.
2021		J. Ellroy Widespread Panic 176: A wigged-out wheelman with pizza-pus zits.