Green’s Dictionary of Slang

unglued adj.

unstable, emotional, lacking control.

1930		see come unglued
1968		‘Hy Lit’ Hy Lit’s Unbelievable Dict. of Hip Words 43: unglued – Frantic; falling apart [...] out of control.
1987		C. Hiaasen Double Whammy (1990) 139: Your friend is totally unglued.
2000		W. Shaw Westsiders 201: Right now, the guy’s completely unglued [...] He’s trying desperately to hold on to his sanity.

In phrases

come unglued (v.)

to become mentally and emotionally unstable.

1930		Dundee Courier 8 Aug. 11/2: You are some weeper, kiddo [...] Pull yourself togwether or you’ll come unglued.
1954		Wodehouse Jeeves and the Feudal Spirit 108: It seemed to me that the great brain had at last come unglued, and this saddened me.
[1954		‘Hot Rod Lexicon’ in Hepster’s Dict. 2: Come unglued – To have engine break down or come apart].
1963		M. Braly Shake Him Till He Rattles (1964) 64: God, if those cats at the school board ever get hip to you they’ll come unglued.
1963		M. Braly Shake Him Till He Rattles (1964) 40: Baby, the way you blow, Fatha will come unglued.
1977		C. McFadden Serial 38: Kate’s practically coming unglued.
2012		M. McBride Frank Sinatra in a Blender [ebook] No Buts was breathing heavy. Sid could see him coming unglued.