having had four teenagers who at one time or another used something........this is a sticky situation. i'd be surprised if anything can get him to quit at the age of 16. all of our kids went into treatment centers and came back out and used. one got kicked out for using while she was in treatment. i'd talk to his mother and him.......i'd tell him how very scared that i am about his behavior and what you see happening to him if he keeps it up.......we did the intervention thing one time on a teenager and his family and his family wouldn't speak to us UNTIL he broke all the lead glass windows on the bottom floor of their home........this is a very tough one to call.......i wish you all the luck that you can use and i'll be thinking of you and your friend and his family........xoxoxo pat