I do not believe that it drastically changes a person's appearance. I think it changes how we perceive ourselves. We are depressed so look in the mirror and pick apart every flaw we see and convince ourselves that we are hideous.

I have a friend that if she's happy then in her mind she's the sexiest most irresistible woman that's ever lived. When she's depressed everyone hates her and she's so ugly she should wear a paper bag on her head. Those perceptions are just in her head because when I look at her she looks the same.