When I was a kid in Oxford, the local "loonie bin" was at Littlemore. This was used as a term for someone who was mad - or with whom we disagreed. I guess this is the same for most if not all parts of England More recently, in Plymouth, I heard someone whose grasp on reality was fragile described as "a bit care in the community". But my favourite is the phrase Norman St John Stevas is said to have used to desribe Maggie Thatcher - "three stops short of Dagenham".