As was said earlier you have to stick to your guns. A thirteen YO female relative started on 'recreational' drugs and is now 17 yo drop out, extremely depressed, self harming, no future, a physical wreck, smoking 20 'joints' a day and whatever else - all because it got out of hand. parents dont know what to do now. Expect the worst and it can only be better. Good luck.
whenI was told about my sons drug taking, I must admit I exploded and threatened to string him up (just words meant to scare him). or course I was the bully, thug call it what you will.
I did ask him what he would have thought if I said to his mother "I dont want to knowm YOU deal with it!" what kind of father would that make me.
"Not a very good one", he said it not me. His mother heard it too.
I said to his mother because this is putting a strain on our marriage. If it meant that he stays away from drugs then I would do it again!