Well, I'm through with depression and I don't have any mental disorders that I know of so what I'm going to say might not do much for you. 
Whenever I get writer's block, it's usually because I've been on the same story/rp post/artwork for too long, or I haven't done any of that in a while. To bring back my creativity, I just play Persona 3 and I'm good to go xd. 
Jokes aside, viewing the works of beginner artists (if we consider writing as art) can really spark MY creativity. To go with that, reading what I've already written helps me by reducing the creativity I need to continue since I can just make the next logical step; like how 1+2=3.
I have friends that read a better writer's work to reduce writer's block but I find that depressing and only do it when I'm sure I'm positive enough to not criticize myself into a writer's block. I'd also advice making a simple draft first and expanding on it as time goes on. Whatever works for you I guess.