Is it permissible to divorce a wife afflicted with schizophrenia, who had been suffering from the illness prior to marriage, and who threatens to kill her son and commit suicide?

There is no sin upon a man for divorcing his wife if he is harmed by her illness. However, it is preferable for him to seek her treatment and assist her with remembrances (dhikr) and incantations (ruqya), so that Allah may heal her and their marital life may become stable.