off one’s trolley

Definition

Slang

  • adjective deranged, unstable, crazy. A variation on the off one’s block theme, which has been popular in British speech since the 1970s. The original image evoked may be of a child losing control of a cart or scooter, or of a patient falling from a mobile stretcher or frame.
http://www.dictionarycentral.com/definition/off-one-s-trolley.html