That is all nice and helps as long as you don't reverse the reasoning like: Oh you can't view/feel depressed, well then just work on it more. For many the gap is just to big... no matter how much effort they put in it.
For example, if you slipped and twisted your ankle, you wouldn't ignore and think there is no solution. You sit down and hold your ankle and then limp to bed, get rest and stay off of it until it was better. Even if you didn't want to.
But problems of the heart, our feelings and our minds, they seem to get in the way of doing things that would actually help you get better.
So, maybe you just have to believe other people and try something new. Because just maybe there's hope, and doing something different for awhile can make something better eventually.