Jan. 21, 2002 - Question: I am desperately looking for a drug-testing facility in my area. I have a 14-year-old son, whom I believe is using marijuana, and I would like to have him tested so I can act accordingly.

Answer: It's a topic that even the U.K.'s royal family has had to deal with lately: teens using drugs. Reports out now tell of Prince Harry admitting to his dad, the Prince of Wales, he indeed smoked marijuana last summer and drank at a local pub. The teen's confession led to a tour of a drug rehab center, where his dad had hoped his son would learn about the dangers of drug abuse.

That makes for a nice storybook tale -- but what do you do when you believe your suspicions as a parent are not being met with some straight answers? More and more parents are turning to drug testing as a way to know for sure whether their kid's personality changes are part of normal development or a festering substance-abuse problem.

Luckily for you, there are more testing options available to the general public now than before. Some involve buying a kit from the local drugstore that lets you test your child's urine for drugs such as cocaine, marijuana, opiates, amphetamine, methamphetamine, and PCP. You also can consider marching him down to a local laboratory that will do the testing for you.

But whichever test you choose, keep in mind that it's only a tool. It's more important to maintain open lines of communication with your son, whether you decide to test him or not.

"The experts tell you that the earlier you begin discussing with your children about drugs and their impact on the human body and what drug addiction can do to you, the better," says Harden Wiedemann, chief executive officer of Assurance Medical, a drug-testing firm in Dallas. "It's not a good approach to wait until the kids are finally using."

But if you have pretty good evidence that your teen is using drugs, testing could open the dialogue and let your child know you take the issue seriously. On the other hand, parents can go overboard by testing a child for no reason and damage an otherwise trusting relationship. It gets particularly tricky if you try to test your child on the sly by quietly clipping a lock of hair. Secret testing can backfire on you and actually reduce trust level between parent and child. It can also be bad strategically, because part of a drug test's value is its deterrent effect. If a teen knows she'll be tested, she may be more willing to turn down the next opportunity to use an illegal drug. In fact, drug testers argue, she can even use the excuse that she'll be screened as an easy way to fend off peer pressure.

All this testing, though, makes civil libertarians nervous. Schools, particularly private ones, are starting to use drug testing as a prerequisite for participation in athletics, extracurricular activities, or even admittance to the school in the first place. But, while schools must navigate the privacy rights of their students carefully for legal reasons, parents generally don't have much worry; as long your child is a minor, you are legally responsible for him or her and can require drug tests.

So let's assume you've talked with your child about drugs and believe that testing would be an important deterrent. You have several options:

• Home urine-testing kits. These have been available in drugstores for a couple of years, and many have been FDA approved. You should still be careful, however, about finding one that has a high reliability rate, and they vary. The tests work in two parts. The first step is to get a urine sample from your teen and use the instant-testing strips, which tell you whether he may have been using any of several common drugs. If you get a "possible" positive result, you take the second step, which is to send the sample to a particular laboratory for a more comprehensive and reliable test. It's important not to rely on the results of the preliminary test strips because they really require confirmation in a lab. These tests can usually pick up drug use within the past 24 hours to 72 hours, though marijuana use can be picked up for about 28 days.
• Hair testing. You can take a lock of your teen's hair and send it to a company in Massachusetts, which will examine it for marijuana, opiates, cocaine, PCP and methamphetamines. The kit, made by Psychemedics, is available in drugstores and over the Internet. After you send in the hair sample (a small amount cut close to the scalp -- hair from a hairbrush doesn't work), the lab conducts the test. You can call a toll-free phone number for results within five days. The benefit of hair testing is that it picks up drug use from a 90-day period. But there's concern that drugs could collect more in darker hair, causing a higher likelihood of a positive result.
• An outside lab. There are lots of so-called "collection centers" out there, mostly for use by employers who send their workers in to drop off a urine sample for testing. Many of them will accept a test request from the general public. To find one near you, try the phone book or visit the Drug and Alcohol Testing Industry Association's Web site. Check its database of local drug-testing facilities. It's not a complete list, but it will get you labs that are more likely to be accredited by their industry organization.
• Options in the works. New, less-invasive innovations in testing are being developed for industry but could eventually work their way to the "concerned-parent" market. For instance, next year a new saliva drug test will be introduced for use in the workplace. The idea is to get away from embarrassing and expensive "pee-in-a-cup" procedures. Another firm, Mistral Securities of Bethesda, Md., has come up with a treated cloth that is wiped across a surface (such as a table or a backpack) and sprayed. If the cloth turns color, that surface has been contaminated with marijuana or cocaine. The kit is available in some drugstores.

While you're at the drugstore picking up one of these kits, make sure you also stop at the bookstore (or check the Web from home) to get guidance on how to talk to your teen about drugs. Wiedemann recommends collecting information on the addictive qualities of drugs and how they affect the brain, and using that as ammunition in a parent-child talk. "We started talking to our son at age 6 about what drug addiction can do to you," he says. "You never know genetically what your makeup is and whether you are prone to addiction. Give them the information and let them make up their own mind. You just have to hope they are smart enough to conclude it's not worth it."