I would like to see if there are any good case studies of people who are not religious who had similar break downs?
That is an interesting question, though I think finding them would be sort of a chicken-egg problem. If someone is not particularly religious, but due to mental illness onset experiences visions, voices or other seemingly supernatural phenomena, they might well become religious to explain what is going on. I am guessing that a person seeing visions or hearing voices would be more likely to think it is something external e.g. God is talking to me, or demons are stalking me, than internal, e.g. this is a product of my brain not working right.
But maybe the people who weren't or aren't religious are the ones who think that aliens or the CIA are talking to them and sending them signals rather than God. I wonder how many of those people are violent as well as delusional?