In a criminal justice setting, it's very hard to create a therapeutic environment where people do feel safe, but the real important thing to do is to do your best to do that.
The thing we want for all our kids is that they be connected with a learning community and that they have strong social and familial relationships. If we can do whatever we can do to create that and to reduce bullying and to reduce the kind of pain and shame so many kids feel for so many reasons, that stuff is going to reduce drug addiction.
If you're worried about a kid and drug use, the safest, best thing to do is individual counseling or family therapy, none of which will expose kids to more deviant or problematic peers and both of which are proven to be effective and at the very least, they won't hurt.
A lot of addiction actually ends by age 30 - something like 50 percent of all addictions with the exception of tobacco - and I think a lot of what's going on there is that the self-control areas of the brain are finally developed enough to be able to stop yourself from relapsing or just continuing. There is a maturational aspect to it as well.