I am a Christian myself and I have to say that I am appalled when preachers (or the likes) say that sin is the cause of mental illness. Sad to say, I have come across that myself with some of the groups I've gone to. When that happens, I just leave it. And I come to find that they are not really right with God.

There are many stories in the Bible about those with depression. Job, David, Elija, and others that I can not think of now.

I remembered that just before last Christmas, someone had posted a video on here of a preacher saying that sin is responsible for depression. I don't know if you remember that. I stated my objection to that.