chemically imbalanced vs disturbed

chemically imbalanced

adj
  • Mentally ill. 

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

disturbed

adj
  • Showing symptoms of mental illness, severe psychosis, or neurosis. 

  • Extremely alarmed; shocked. 

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