off one's trolley

Prepositional phrase

1. (humorous, idiomatic, informal) Having gone mad; insane.
   • The Romance is the best part of the four movements. One is a bit off one’s trolley at such times and I should surely write a better Suite at this time after twenty years of sober reflection.1919, American Guild of Organists, edited by Thomas Scott Buhrman, American Organist, volume 2, page 409
   • On the whole, bodily symptoms have at least the consolatory fact about them, that they replace mental symptoms, fears of going off one’s trolley; and I suppose that, if I got rid of all the physical symptoms, things would but have been cleared away for a new worry about mental ones?1915–1981, Kenneth Burke, Malcolm Cowley, edited by Paul Jay, The Selected Correspondence of Kenneth Burke and Malcolm Cowley, 1915–1981, Viking, published 1988, →ISBN, page 30