Q: Our 17-year-old has completely fallen apart! In less than a year, he’s gone from being an outstanding honors student, athlete and well-mannered young man that all of his teachers, coaches and friends raved about to being a mediocre (B/C with the occasional D) student who has decided he’s had enough of playing sports. His attitude has deteriorated as well. He’s often surly and disrespectful. We know he began smoking pot around the same time the downturn occurred, but he assures us he’s not doing that anymore. He says he’s just tired of being “Mr. Goody Two-Shoes.” We took his car away for a few weeks, but that had no effect. As he begins his junior year, we are concerned that he’s trashing lots of potential opportunities. Any advice would be appreciated.

A: I’ll eat my favorite Panama hat if your son’s not still smoking marijuana on a regular basis. You’re describing precisely the effects pot has on motivation and social behavior (attitude). Deception is a feature as well, including denial of continued use. The research strongly suggests that marijuana use has a very adverse effect on teens.

My take is that you are being very naïve, probably because your son has given you little problem to this point and you want to believe these problems are temporary glitches. That may be, but then again, this could be the beginning of a much more destructive decline. I’ve heard too many horror stories to recommend a “wait and see” attitude at this point. You want to believe him, of course, but in the course of doing so, you’re close to becoming enablers.

You did well by taking his car away, but you blew it when you gave it back after a few weeks. The two most likely reasons that that didn’t have any effect are (1) you didn’t take the car away long enough and (2) he knows you’re too soft-hearted and easily manipulated to do so. So he just waited out the punishment.

Schedule him for a surprise drug test. Assuming that comes back positive, you sit him down and tell him that he (1) will undergo random drug tests (once every four weeks on average) until he’s been clean for nine months, (2) will begin seeing a drug counselor who specializes in working with teens and (3) will have no use of a car or cell phone until he’s been clean for five months, his grades come up, he’s back in at least one sport and his attitude at home improves dramatically.

In the small likelihood that the drug test comes back negative, sit him down and inform him of (3) above: that you will take his car and cellphone until he is back on track and stays there long enough for you to know that his improvement is not fleeting.

Time’s a’wastin’!

Visit family psychologist John Rosemond’s website at www.johnrosemond.com.