My addiction, pre-Christ, was Rx stuff. Somehow, I had a big Rx for Adderall and lots of various downers (Ativan, Klonopin, etc.). That's a bad mix, btw.
Part of what helped me was Teen Challenge (no, its not actually for teenagers these days, lol). They think of addiction as a sin to be repented of and use 1+ year programs to change behavior, too. At that point, I wasn't addicted, but I was burned out from the pills (again: drugs are bad, mkay?), so it was quite helpful, lifechanging even.
I think...I think God is merciful, but He also has certain expectations. And not all addictions are the same. If I still had crazy anxiety and --had-- to take a benzodiazepine, I think God would understand. Same thing for pain management, and (I think) medical marijuana. Not all drug use is drug abuse.
Having said that...some people need a while to work through an addiction. With drugs, sometimes just detoxing can be a painful experience (alcohol, too). And...I've seen first hand how some people trade an addiction to chemical X for a high intensity form of Christianity. Or they can get addicted to work, seeking status, etc. I don't know if counseling or what helps in that situation, or if its the Holy Spirit's gradual work in someone's life to change what drives them, but...yeah. I think God is more merciful than we give Him credit for, and He seems to show mercy to the humble, so...a repentant (alcoholic, drug addict, pill head) is probably given more grace than an unrepentant (insert major sin --here--). My theory, of course.