I am suspicious that my 16-year-old son may be using some kind of illegal drugs. He’s just not himself lately, and his friends are some of the weirdest guys you ever saw. Can you summarize the most common symptoms of drug abuse? What should I look for?

A complete answer to that question would fill a book, because there are so many illegal substances on the market today and each has its own characteristic “fingerprint.” But there are eight common physical and emotional symptoms you might look for in your son.

l Inflammation of the eyelids and nose is common. The pupils of the eyes are either very wide or very small, depending on the kind of drugs internalized.

• Extremes of energy may be evident. Either the individual is sluggish, gloomy and withdrawn, or he may be loud, hysterical and jumpy.
• The appetite is extreme — either very great or very poor. Weight loss may occur.
• The personality suddenly changes; the individual may become irritable, inattentive, and confused, or aggressive, suspicious and explosive.
• Body and breath odor are often bad. Cleanliness is generally ignored.
• The digestive system may be upset — diarrhea, nausea and vomiting may occur. Headaches and double vision are also common. Other signs of physical deterioration may include change in skin tone and body stance.
• Needle marks on the body, usually appearing on the arms, are an important symptom. These punctures sometimes get infected and appear as sores and boils.
• Moral values often crumble and are replaced by new, avant-garde ideas and values.

Let me caution you that some kids are able to hide their drug use better than others. You might stop by to see the officer in charge of narcotics enforcement for your local police department. He or she may be able to give you more specific information applicable to your son.

What about snooping through my son’s room to see what he might be doing? Do you think parents should do that?

There are definitely times when mothers and fathers need to conduct their own quiet investigation, even though it might invade the privacy of the teenager. This issue was discussed widely in the media some years ago when comedian Carol Burnett discovered her teenage daughter was a drug user. When the problem finally came to light, Carol was regretful that she hadn’t taken steps to inform herself of what was going on. She appeared on many talk shows to say, in effect, that kids desperately need their parents to “catch them” in a moment like that. Don’t let your respect for their privacy cause you to stick your head in the sand and fail to notice what is going on right in front of you. I strongly agree.

Of course, parents have to “know” their children, too. There are some who would never do anything illegal or harmful. It’s just not in them. In those cases, I would not recommend snooping through their room and private stuff. But in situations where a secretive boy or girl is doing suspicious things, running with the wrong crowd, and then demanding utter privacy at home, I would gather whatever information I needed in order to know how to respond.

My 14-year-old boy is flighty, mischievous, irresponsible and lazy. If I don’t watch him very carefully, he’ll find ways to get into trouble — not really bad stuff, just stupid kid behavior. But I’m afraid I could lose him right at this time. What can I do to keep him on track?

It is most important to keep your rambunctious youngster moving. If you let him get bored, he’ll find destructive ways to use unstructured and unsupervised time. My advice is to get him involved in the very best church youth program you can find. If your local congregation has only four bored kids in its junior high department and seven sleepy high schoolers, I would consider changing churches. I know doing that could be disruptive to the rest of your family, but it might help save your volatile kid. This can be done not only through church activities but also by involvement with athletics, music, horses or other animals, and part-time jobs. The hope is that one of those options will grab his fancy at some point, and his boundless energy will be channeled into something constructive. Until then, you must keep that energetic kid’s legs churning.