"Fairy tales are more than true: not because they tell us that dragons exist, but because they tell us that dragons can be beaten." ― Neil Gaiman, Coraline.
So what does your dragon look like? Mark has referred to his as the black dog. I think mine is more a leviathan as I seem to get swallowed up in it like Jonah. And is it even helpful to see depression as a dragon?
For me it is. In the old days, before I knew what was going on, I would be riding on the crest of a wave, effortlessly on top of everything and then, without warning, the lights would suddenly dim, the world would retreat behind a plate of thick plate glass (fogged and obscured glass at that), sound would become distorted and dim and all I could feel was lethargy.
I would drag myself to the doctors and get yet another diagnosis of over-work or post-viral exhaustion or – occasionally – depression attached to whatever events were going on in my life at that time.
So now, seeing it as being inside a metaphorical whale is quite helpful. There's not much to do, there's not much oxygen, so I couldn't do it anyway. Yes, it's very dark and smelly and generally unpleasant. But, eventually, if I just sit tight and wait, after a few months, the whale will vomit me out again. He's done it every time before; he'll do it again. I have to have faith.
The secret is to make it harder and harder for him to swallow me. Now I know what's happening I make sure I don't ride that wave too high and hard (he's waiting the other side of it). I make sure I'm rested and strong and I've done my mental balancing exercises.
The last time I fell into his mouth I think I got stuck in his throat: there was still some daylight and fresh air around and it wasn't quite so smelly. He spat me out too after six weeks instead of six months. Now, that was a result.
I don't ever want to make a pet of this Leviathan; he's the enemy and getting too comfortable with him would be a mistake. But I do want to study him, learn about him, treat every interaction with him as a chance to weaken him and strengthen myself. One day I will defeat him. Dragons can be beaten.