Karen, I'm so sorry. I also have had a mental illness, so I understand your feelings. When people smugly say your mental illness is sin, or caused by sin, they have no idea what they mean. In my situation, I would definitely argue that there were spiritual forces behind my mental illness, but there was also stress and other factors. So it can be caused by bad choices (sin if you like) but each individual situation is DIFFERENT, and people NEED TO UNDERSTAND THAT. Btw, I'm healing from mine - very very well with God's help. I hope you heal up too.
This lack of understanding nearly cost me my life. I understood mental illness is illness but my own brother said it was from the devil and I should push it out of my mind. His wife believed God was punishing me for some sin I stobbornly refused to confess. These two run in very conservative circles but they live in a highly populated area so there isn't so much isolation. I live in a large metropolitan are far from them. It's a good thing too. I was able to get help from the secular community, not that it was a piece of cake. What causes this refusal to accept that a depressed person is sick?