My sympathy to those touched by this subject. JWs do have above average mental illness. Some bring it in with them, while others develop it due to the terrible nature of the WT. People in any religion are not immune to suicide. Truly our only hope is in the true God/Jesus/gospel. True believers are not immune to depression, etc., but He has the power to make us whole. Satan comes to rob, kill, destroy. Shame on the WT for being a channel of demons instead of God.
It is false assurance to think that one can be a JW, commit suicide, be resurrected for another chance. The issue is still receiving or rejecting the true Jesus in this life (a true believer who struggles and commits suicide is not the same as an unbeliever or false cultist who does the same).