addiction vs hobby horse

addiction

noun
  • The state of being addicted; devotion; inclination. 

  • A pathological relationship to mood altering experience that has life damaging consequences. 

  • A habit or practice that damages, jeopardizes or shortens one's life but when ceased causes trauma. 

  • A state that is characterized by compulsive drug use or compulsive engagement in rewarding behavior, despite negative consequences. 

hobby horse

noun
  • A topic about which someone loves to talk at great length. 

  • A child's toy consisting of a (usually wooden or cloth) horse's head mounted on a stick. 

  • The Irish hobby, an extinct breed of horse. 

  • A puppet-like costume used in some traditional dances and festivals that gives its wearer the appearance of a man on horseback. 

  • An early bicycle with no pedals or brakes; a draisienne. 

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