This is a very good topic and I am grateful for the informative posts on the subject.
I also know somebody who has schizophrenia. They take medication but have still had breakdowns because of stresses of life. Their non-JW family feel the religion is partly responsible. This person is still active and I would never think of telling them my negative feelings about the religion for fear that they couldn't deal with it, so I keep silent.
I am not an expert but I can tell you that I developed O.C.D. while being in the religion. I have read that this may or may not have a hereditary cause. While I will never know if I would have developed O.C.D. anyway, I strongly suspect that the religion had something to do with it.
LHG