I think I know what you're saying. My point is that mental illness is nothing that you or I would ask for. I cannot pick my skin color. You cannot pick your eyecolor. Neither of us can pick the parents from which we came. As a result I feel that my chemical makeup was beyond my control. This line of thinking helps me personally to live free of guilt and shame and allows me to work consistently to improve my condition.
I agree with Mike_J as well about the trauma or upbringing also playing a key role. How I don't know ...but DEFINITELY!