depress vs overstrain

depress

verb
  • To bring down or humble; to abase (pride, etc.). 

  • To cause a depression or a decrease in parts of the economy. 

  • To make depressed, sad or bored. 

  • To press down. 

  • To reduce (an equation) in a lower degree. 

overstrain

verb
  • To subject to an excessive demand on strength, resources, abilities, or the imagination. 

noun
  • excessive strain 

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