Just to add to that, I'll tell you a little short story about working in a group of 15 offenders in a medium-security prison here, all of whom were in a gang. My question to them was, “What's the number one thing that keeps you guys coming back to prison and keeps you being losers?” Their response was alcohol and drugs and their own consumption of it, not so much their ability to sell it, but absolutely their consumption of it. Do they participate in the selling? Absolutely, but more or less to support their own lifestyle, which is really about the consumption component.
My major objective when I'm working with them individually is to point out to them that with the substances they continue to use, especially if it's soft substances or some that are legal now, like alcohol, what they continue to teach themselves are inappropriate coping skills. Any time something goes wrong, it's “have a joint” or “have a drink”. But that's the wrong answer. That's the coping they teach themselves and that keeps them stuck in their lifestyles.
I'm not sure if that directly responds to your question, but it is a significant issue.