disturbed vs unstable

disturbed

adj
  • Extremely alarmed; shocked. 

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

unstable

adj
  • Unpredictable. 

  • Readily decomposable. 

  • Not stable. 

  • Radioactive, especially with a short half-life. 

  • Fickle. 

  • Having a strong tendency to change. 

  • Fluctuating; not constant. 

verb
  • To release (an animal) from a stable. 

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