because they're in constant conflict with themselves and reality.

Yes, she is but I think that at some point many of us experience this struggle inbetween reality and ourselves.

I was "there" as well but I did not label it as "depression" it was a part of my path to allow myself to fall in a dark hole because I realized it's so much more special and euphoric to dance towards the light.
Without knowing the dark we don't know the difference. It takes a while to find our purpose and we might even loose it again but I call this "being simply alive" and live life as it presents to us, like a roller coaster ride. I enjoy the Ups after the downs. My bipolar friend said a day ago : "the Ups are so much more fun".
Acceptance comes with experience. Some people need to thrive in sadness because it's a safer place for them, maybe scared of the happiness they would deserve.
I hope this makes sense.