I too wonder if some people have gone so far "under" that they can't stop
I have seen many miracles during my almost 7 yrs in the program of al-anon - I have seen people grab ahold of a recovery program and walk away from drinking/using/gambling etc and embrace a new way of life. They have struggled but not relapsed.
Then I have seen those who continue to try and try and try but are never able to fully give themselves completely to this new way of life and are never able to fully walk away from their addiction. Some of them continue to try - which I do admire in them - sadly some them give up and continue on their downward spiral.
So I guess - what my answer would be to your question - is it is an individual thing - some do make it, some don't - but I believe it is not up to us to know who will or who won't.
It's between that person and their willingness to allow their HP and the program to work in them.
As long as they are willing - there is always hope.
But many times we do have to detach ourselves from them and their issues to be able to make healthy and wise decisions for ourselves and our children when they are not embrace recovery.
Wishing you and your children, your HP's very best!
HUGS,
Rita