Yay! Glad they finally put this to rest. I was hopeful but extremely pessimistic about it, and now we know.
It's so cool to me how many specialists we have around the world, like Jain (the copper-sulfide expert). That's such a very specific thing to be an expert about.
In my work in devops with a start-up, I'm expected to know a bit about everything. I'm a bit jealous of Jain's extremely narrow focus, lol.
I had 2 interventions in my life and neither worked. In fact, they made it much worse for me.
I suggest that you go to AlAnon and learn a bit about alcoholism before trying anything (btw, AlAnon is not AA, but is a program to help non-alcoholics understand what they're dealing with.)
Your friend is lucky to have you. Don't give up on them. It truly is hellish, and they'll need your support.