Q: We recently discovered that our 16-year-old son has been smoking marijuana on a regular basis. At first, we intended to begin using an over-the-counter drug test but then learned that teens have figured out how to beat these tests. One of our son’s friends, for example, was regularly tested at home and always tested negative despite the fact that he never stopped using. Also, do you think he should go into counseling?

A: You’re right, many drug tests are not reliable and teens have learned how to fool them. I searched “fooling over-the-counter drug tests” and discovered that doing so requires no special expertise or anything more difficult to obtain than lemon juice or vinegar. Apparently, concealing marijuana use from OTC tests is almost laughably easy. As one expert commented, drug testing has turned into a “cat-and-mouse game.” I’d recommend that you ask your son’s physician how you can go about enrolling your son in a reliable, professionally-administered drug-testing program of the sort used by the airline industry and law enforcement agencies.

In the meantime, fulfill your responsibility to the community by taking away your son’s driving privileges until he has passed at least one year of randomly-administered tests. Make no mistake about it, marijuana and driving do not mix. In May, 2016, AAA reported that fatal automobile accidents involving drivers who had recently smoked pot doubled after Washington state legalized the drug. The additional problem is that your son may be especially susceptible to marijuana’s effects. It’s been discovered that impairment levels vary widely from person to person. I can’t emphasize enough: Get him off the road!

Obviously, your son is running with a bunch of like-minded peers in which case you should apply appropriate restrictions to his social life. The message you send to him should be “find new friends or we are your new friends.” Yes, he will probably be able to go around your restrictions to some extent, but restrictions in combination with random drug testing will be fairly effective.

Last but certainly not least, take away his lifeline to his current peer group. I’m talking about his smart phone. As I’ve said many, many times in this column and on my weekly radio show (American Family Radio, Saturdays, 6:00 PM ET) there is no rational justification for giving a teen a smart phone. They are anti-social devices and researchers have discovered that they induce physiological effects that are similar to those induced by addictive drugs.

Confiscate the current phone. Obtain a basic cell phone (believe it or not, most providers still carry them) that can’t access the Internet and doesn’t facilitate easy texting. Give it to him only on those occasions when you want to be able to get in touch with him or vice versa. That is all the phone any teenager needs anyway.

As for counseling, I don’t put much stock in it, especially when the patient is a teen who doesn’t want to be counseled in the first place. Don’t waste your — or your insurance plan’s — money.

None of this is going to be easy, but the eventual payoff is a child who is drug-free, whose friends are drug-free, and because of no smart phone, has greatly improved social skills. Hang in there!