For me the worst part about depression is the feeling of hopelessness, as if things will never get better and nobody in the world even cares. I find myself thinking about the world and how people treat each other quite a bit when I'm depressed and it only makes it worse because I can only think of the bad things.

The other thing I hate about it is that when you feel like you've concurred the physical and mental symptoms they get worse and you have to start all over.