I understand that. I was on prozac for years. I chose to come off it because it was messing me up, otherwise I'd have been happy to take it for the rest of my life (why not?)
I was aware that if the blackness returned and going back onto prozac failed to work (which can happen) then my lifespan would be a few months at the most.
People without really bad depression can't understand how bad it can be. Death really is better.