Green’s Dictionary of Slang

1. crazy, over-reacting; fascinated.

1952		(con. 1948) G. Mandel Flee the Angry Strangers 432: Nuts; you dig? Plain nuts, flipped.
1956		H. Whittington Forgive Me, Killer (2000) 98: You’ve gone nuts. You’ve flipped.
1967		H.S. Thompson letter 28 Aug. in Proud Highway (1997) 636: They thought he was just another of my flipped-out lawyer friends.
1967		W. Murray Sweet Ride 70: I played this creepy teenager, sort of a maniac, who’s flipped on LSD and grass and sex, oh, everything, the whole scene, see?
1979		G. Swarthout Skeletons 188: You’ve flipped, freaked out, Tyler.
2002		Fabian & Byrne Out of Time (ms.) 145: They said he was doomed, flipped-out, and I knew he was because I’d been there when it had happened.
2021		T. Swerdlow Straight Dope [ebook] [H]e’s so flipped out he’s off somewhere making believe he’s going to kick.

2. intoxicated with drink or drugs.

1996

Eble Sl. and Sociability 45: Among the synonyms for drunk are [...], crispy, flipped out, fried.