Question number one...if violent has he ever hit the wife or kids and how long has this been going on? If Yes, ones hit never stops...she has to leave - to help him. To help him, he has to help himself, lazima akubali yeye mwenyewe kwamba anatatizo.
I have seen alcoholics who even when they suffer backouts they still refuse they have a problem. Akikubali anatatizo, kuna counselors wengi wanaweza kumsaidia kudeal na tatizo. Akikataa anatatizo just pray, and possibly his best friend(if he is not an alcoholic....to assist him in the journey to realise he has a problem). Please make no mistake, children growing and seeing what papa does, imprints in their hearts and brain.
Also, look at some events which may have triggered this behaviour/behavioural change. I guess he was not an alcoholic when they got married? Return to the source that is where the answer lies.