Email Question Concerning Divorce Revisited

I have heard the only time a divorce is okay in the eyes of God is when a spouse commits adultery. Is this true? What is a wife of 28 years supposed to do when she's had enough of her husbands verbal and physical abuse, alcoholism and drug problems, and occasional gambling problems? Is she right to finally wake up and want a divorce? Would God want her to continue suffering??? I think she needs to pack her bags and never look back, but what is the biblical answer???