Going on Leave for Sz

I seem to be over my month long depression/nap. The only thing is I decided to leave my job in the process of my long nap. What process do you have to go through so that you can get qualified time off for mental illness? I have always just picked myself up and went and got another job when I was better but I am getting to the point where my sudden leaving of many jobs might make me unhirable in the eyes of many. Does anyone have any experience with this whole qualified time off thing?.