nightmare vs trauma

nightmare

noun
  • Any bad, miserable, difficult or terrifying situation or experience that arouses anxiety, terror, agony or great displeasure. 

  • A very bad or frightening dream. 

  • A feeling of extreme anxiety or suffocation experienced during sleep; Sleep paralysis. 

verb
  • To have a nightmare. 

trauma

noun
  • An event that causes great distress. 

  • An emotional wound leading to psychological injury. 

  • Any serious injury to the body, often resulting from violence or an accident. 

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