There was an ex JW counselor who wrote about this. Jerry Bergman perhaps. In any event, he thought the rates of mental illness were higher among JWs. I have known quite a few who ended their lives in one way or another. Here are some resources:
https://www.ncbi.nlm.nih.gov/pubmed/1174772
https://www.amazon.com/Jehovahs-Witnesses-Problem-Mental-Illness/dp/9993195286