MARIJUANA ISN'T A HARMLESS DRUG

Before Thomas Clark advocates the use of marijuana in moderation or
suggests policy changes toward that end, he needs to look more closely at
the scientific facts ("A realistic prescription," Focus, Nov. 1).

In the first place, classifying drugs as either "hard" or "soft" is off the
mark. All drug use is potentially dangerous for many people, and it is
impossible to predict who will respond particularly badly. Marijuana is
neither "soft" nor "benign"; rather, it is a drug with a high potential for
abuse.

In fact, every year more than 100,000 people, many of them adolescents,
seek treatment for their inability to control their marijuana use. Most
people who are knowledgeable about addiction would qualify this as an
addictive drug.

Another science-based reason for not condoning marijuana use comes from a
recently published study by a Harvard researcher showing that use of any
illicit drug, but especially marijuana, significantly increases the
probability that an individual will abuse other drugs during the course of
a lifetime.

Moreover, science has shown that short-term use modifies learning, memory,
emotional state, perception, and the motor skills necessary to drive a car.
And studies have shown that prolonged use can alter the lungs and immune
system in ways that last long after the individual has stopped using
marijuana.

The bottom line is that marijuana is not a benign drug, and its use should
not be encouraged.

Alan Leshner
Director
National Institutes of Health
Rockville, Md.

Checked-by: Richard Lake