My son Johnny, a high school junior this fall, is learning all kinds
of new things -- academic, social and physical. At 16, he seems
fearless. And, as a typical American teenager, he faces two
risk-sensitive issues: drug use and sexuality. So I read with keen
interest a recent report by the Centers for Disease Control and
Prevention that addresses both of these hot-button topics.

Its gist: Teen drug use is up, but fewer young people are having sex,
and more of those who do practice ''safe sex.'' A decade ago, a third
of students surveyed said they had experimented with marijuana. By
1999, almost half had tried pot. But during the same time span, the
number of students having sex declined from just over half to slightly
under half. Most important: Of those who were sexually active, 58%
reported using a condom in 1999, compared with 46% in 1991.

I wanted to know why risky teen sexual activity decreased while drug
use rose. A look at our sex and drug education offers an answer: In a
nutshell, while we'd all prefer that they abstain from both, we try to
reason with teens about sex, but we scare them about drugs.

School-based drug education, its roots in the early 20th century's
temperance movement, has used a variety of tactics to frighten young
people away from using drugs. But too many still offer 1930s-style
''Reefer Madness'' messages. As the federal prevention budget has
increased, teens have been bombarded by anti-drug school programs and
media messages.

Messages are ludicrous

My strong preference is that my son abstain. But in our zeal to deter
experimentation, we may have gone too far. Many messages we have
delivered to teenagers have been ludicrous (''this is your brain on
drugs'') or grossly simplistic (''just say no''). The result: teens
who are frighteningly cynical and distrusting about what adults tell
them about drugs.

Sex education began with the same basic ''abstinence'' tenets. During
the 1970s, ''don't do it'' was the predominant message. Then AIDS
came, and discussions about teen sexuality began to focus on the
practical business of saving lives. One crucial piece of information
-- condoms reduce the risk of contracting HIV -- gave educators the
impetus to follow admonitions of abstinence with ''harm reduction''
information. Reality-based sex education acknowledged the value of
postponing sexual activity. It also provided young people with the
how-tos of avoiding sexually transmitted diseases and unwanted pregnancy.

Today's drug-education programs face the same abstinence-vs.-safety
dilemma. No one wants teens to use drugs, yet government surveys
indicate that by the time they reach their senior year of high school,
88% claim that marijuana is ''fairly easy or very easy'' to obtain.
''Harder'' drugs such as heroin are available as well and are cheaper
and more potent than ever.

We are asking young people to abstain in a culture that is hardly
''drug free.'' At a time in our children's lives when they're most
amenable to taking risks, we not only insist that they decline, but we
also offer no practical information for those 80% of 12th-graders who
say ''maybe,'' ''sometimes'' or ''yes'' to alcohol and other drugs.

Prevention is better approach

Parents are terrified that a reality-based, safety-oriented discussion
of drugs will lead to experimentation. But the door already is open,
just as it is to sexual activity. Our goal ought to be drug-abuse
prevention. Teenagers who are determined to experiment need to know
which drugs pose the most risks; that mixing certain substances can be
deadly; and that driving while under any influence must be avoided.

Young people need comprehensive information that they trust. With
science-based knowledge, they will be in a better position to make
reasoned decisions. Abstinence continues to be our preference, but the
promotion of safety must be our bottom line, just as has been the case
with sex education.

Marsha Rosenbaum, directs the San Francisco office of The Lindesmith
Center-Drug Policy Foundation.