chemically imbalanced vs lunatic

chemically imbalanced

adj

  • Mentally ill. 

  • Used other than figuratively or idiomatically: see chemically, imbalanced. 

lunatic

adj

  • Crazed, mad, insane, demented. 

noun

  • An insane person. 

How often have the words chemically imbalanced and lunatic occurred in a corpus of books? (source: Google Ngram Viewer )