What is the ruling regarding a husband divorcing his mentally ill wife, a divorce pronounced by the husband under duress, knowing that he does not desire the divorce?

If you uttered the words of divorce to your wife in a state of extreme anger that overwhelmed your intellect and you were unaware of what you were saying, then the divorce does not take effect. However, if you were aware of what you were saying, then it has taken effect. Stress and shouting are not considered duress. If you repeated the word of divorce intending three pronouncements, then she becomes irrevocably divorced from you with a major separation according to the majority of scholars. But if you repeated it with the intention of emphasis or without the intention of three pronouncements, then only one divorce takes effect. It is advisable to present the matter to the Sharia court or to trustworthy scholars.