I agree with what hello-kitty said above, they're not ready until they are ready and we can't change that...but we don't have to keep a front row seat by allowing them to bring their addiction and chaos into our homes.
I know the pain in your heart, I've walked in your shoes.
Sometimes it takes more love to let go than to keep trying to "help" when it ends up enabling and giving them a soft place to fall.
Try some meetings, they literally saved my life and my sanity.
Hugs