disease vs placebo

disease

verb
  • To infect with a disease. 

noun
  • Any abnormal or harmful condition, as of society, people's attitudes, way of living etc. 

  • Lack of ease; uneasiness; trouble; vexation; disquiet. 

  • An abnormal condition of a human, animal or plant that causes discomfort or dysfunction; distinct from injury insofar as the latter is usually instantaneously acquired. 

placebo

noun
  • The vespers sung in the office for the dead. 

  • A dummy medicine containing no active ingredients; an inert treatment. 

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