If possible, try to get the kids to an Alateen meeting. Despite the name, many areas don't have a lower age limit for the kids attending. With my 6 yo son I used the "disease model" to explain his dad's alcoholism, which worked pretty well. He was putting the blame on himself for his dad's rages and other behavior, so it gave him an explanation that he could understand and he quit blaming himself for "making daddy mad" and stuff like that.