What is the theme in Ethan Frome by Edith Wharton?

One major theme in the story, Ethan Frome, is that of frustration. Ethan is frustrated over having to give up his dreams; Zeena is frustrated over losing her own dreams and having to spend her life on a farm; Mattie is frustrated over having to live off the good graces of her family. Everyone is frustrated in one way or another.