How do I talk to my kids (8 and 11) about their dad being in treatment?

Kids do better with simple truth than with mystery — their imaginations fill gaps with worse. Something like: 'Dad has an illness called addiction. It makes his brain very sick around alcohol. He's at a special hospital learning to get better, because he loves us.' Then the three Cs, which family programs teach for good reason — they didn't Cause it, can't Control it, can't Cure it. The 11-year-old may ask harder questions; answer honestly and briefly. And ask his treatment center about the family program — many include kids' sessions with people trained for exactly this conversation.