Yeah, I get what you're saying about depression and your environment. For me it was nostalgia. I am prone to romanticize the past, and thinking about "happier times" has always triggered depression in me pretty bad, even when those "happier times" probably weren't happier at all. I recently made the decision to live more in the present, and got rid of a bunch of my old belongings I was hanging onto. Of course I'm still depressed as the problem is biological, but I do think living in the past made my depression worse. I'm also in my early 20's, so there's not much past to live in haha.