angst vs unconcern

angst

noun
  • A feeling of acute but vague anxiety or apprehension often accompanied by depression, especially philosophical anxiety. 

  • Emotional turmoil; painful sadness. 

verb
  • To suffer angst; to fret. 

unconcern

noun
  • Freedom from worry or apprehensiveness; insouciance or nonchalance. 

  • Lack of interest or care; indifference or apathy. 

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