I agree with all the wise advice given but i also understand where you are coming from....
my son's addiction spiraled during his college years...by the time he came home (4 years later...after graduation) it became apparent to us that he was in active addiction
I have spent much time wondering if earlier intervention could have helped us avoid some of the tragedies we (he) faced in the following years...
research has shown that those addicts who are diagnosed early and get treatment sooner have the best chance at recovery....
in that sense I'd follow the advice of "get between your child and the drug"
do whatever you can to promote early intervention....(IMO...intervention is not enabling)