disconsolation vs dysthymia

disconsolation

noun
  • The state of being disconsolate; gloom. 

dysthymia

noun
  • A tendency to be depressed, without hope. 

  • A form of clinical depression, characterized by low-grade depression which lasts at least 2 years. 

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