round the bend vs unhinged

round the bend

prep
  • Crazy, mad or insane. 

  • Close to or in close proximity to another location. 

unhinged

adj
  • Not having ever been mounted using a stamp hinge. 

  • Mentally ill or unstable. 

  • Not furnished with a hinge. 

How often have the words round the bend and unhinged occurred in a corpus of books? (source: Google Ngram Viewer )