I have noticed how much Dmitry's health seems to have failed after the revolution. Many have called it stress, some guilt, but I think it amazing how one's emotinal stress and even guilt can do one's physical apperance. Alexandra also underwent a change following Alexei's birth, she physically and emotionally simply started to fall apart.
I can understand Dmitry being depressed after the revolution, in truth who wouldn't be? You lost everything you had ever known and one has to wonder how deep the deaths of his father, Ella, and the Imperial family effected him.
I started to wonder if Dmitry ever read the letter Rasputin sent to the Tsar predicting his death, or heard of it and if he did? Perhaps that caused him to ponder if he had caused the death of his family?
( Just wondering, although I don't think Dmitry believed predictions or such things, but still would like to know if he ever read it and found it rather eerie? I know I do.)