Did anyone ever see that episode of House M.D. where his patient was dying because his bodys immune system was attacking itself? That is essentially what depression is like, your own mind and body turns on you. Low self-esteem is a huge trigger in depression, and as you start to sink deeper you take yourself down with you. Mirrors can become your worst enemy as theyre a constant reminder of just how much you dislike the way you look and who you are. You criticise yourself for every little failure, every little blemish or sometimes youll attack yourself for allowing you to become depressed in the first place. Battling these thoughts is the equivalent of that moment in a marathon when a runner hits the wall, but instead of an imaginary brick wall you have to break through, those depressed see a mirror reflecting back to them what theyre most critical of. There is nothing logical going on inside your head while youre depressed when it comes to how you view yourself, dont make it harder on yourself by believing any of those thoughts swimming around in your mind.