self-abuse vs self-stimulation

self-abuse

verb
  • To harm oneself. 

noun
  • Physical or verbal maltreatment of oneself. 

  • Injury inflicted deliberately upon oneself, especially resulting from a mental disorder. 

self-stimulation

noun
  • onanism 

How often have the words self-abuse and self-stimulation occurred in a corpus of books? (source: Google Ngram Viewer )