Is it permissible to seek divorce from a psychologically ill husband who refuses treatment, out of fear for oneself and one's child?

If the wife fears for herself and her child from remaining with her husband, who refuses treatment, she may refer her case to the Sharia judge to set a period for his treatment. If the period expires and the situation remains unchanged, and she is certain or predominantly believes that harm will result from cohabiting with him, she may request a divorce to avert harm and to ensure her safety and that of her child. There is no sin upon her for doing so.