fixed idea vs frenzy

fixed idea

noun
  • An idée fixe, an obsession. 

frenzy

noun
  • A violent agitation of the mind approaching madness; rage. 

  • A state of wild activity or panic. 

verb
  • To render frantic. 

  • To exhibit a frenzy, such as a feeding frenzy. 

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