Marijuana has been at the front
line of the clash between youth and mainstream culture for so
long now -- and so much misinformation has been told and retold
about it -- that it's probably useful to start from scratch in
discussing it and its potential risks.
Derived from the leaves and flowering
tops of the hemp plant (Cannabis sativa), marijuana is
usually rolled into cigarettes or smoked in water pipes or "bongs"
or hollowed-out cigars called "blunts." Marijuana is
commonly known as "weed," although "grass,"
"pot," and "reefer" are still common terms,
Two other forms of cannabis,
hashish and hash oil, can be made from the plant's resin, but
they're less prevalent than marijuana. What all forms of the
drug have in common is tetrahydrocannabinol (THC), the main psychoactive
chemical in the drug.
According to the Drug Enforcement
Administration, the average potency of street marijuana in 2001
was 4.1 percent THC. That may not seem like much, but it's higher
than levels of 10-15 years ago, when potency averaged around
That extra potency could mean
extra problems for users, since THC tends to stay in the body
longer than other drugs. In fact, traces of THC can be detected
in urine 3-5 days after use, and for up to a month in heavy users.
Subjective effects of THC include
euphoria and a mild disorientation. Other short-term effects
include increased appetite and heart rate, and reddening of the
eyes. Effects typically last 3-4 hours.
Probably of more concern to more
parents, though, is how THC affects the brain. Recent research
shows the drug affects three key brain functions:
- Memory. Pot disrupts short-term memory and increases distractibility.
- Motor skills. Marijuana can slow reaction time and
reduce "tracking ability," which could mean serious
problems for inexperienced drivers.
- Thought. Higher-order thinking is also affected,
including calculation skills and the ability to follow complex
Long-term risks of marijuana
are less clear-cut, but research shows that pot poses at least
some degree of risk in several areas:
- Heart/Lungs. Since marijuana raises heart rate, it
could pose a risk to people with heart problems or hypertension.
And since marijuana smoke irritates lung tissue and reduces respiratory
capacity, which means that long-term pot smokers could be at
risk for many of the same smoking-related diseases as cigarette
- Hormones. Marijuana lowers levels of sex hormones
in both sexes. In children, such changes could affect sexual
maturation and physical development.
- Brain. Research shows that marijuana can interfere with
the process by which short-term memories are encoded and stored
in the brain. And even though such impairment seems to be reversible,
its effects on school grades definitely isn't.
While pot's long-term effects
on memory, motivation, and learning may depend largely on how
much is smoked, and how often, teen users face other, special
That's because the teen years
are the time when kids refine the personal skills they'll rely
on as adults. Successfully meeting challenges, solving problems,
and coping with stress are an important part of this process.
As much as anything, parents should point out the risk of diluting
this important aspect of growing up with pot -- or any other
Other parents worry about the
so-called "amotivational" effects of marijuana: the
apathy and passivity sometimes seen in heavy users. It's impossible
to say whether marijuana actually causes apathy, or if depressed,
apathetic people are just more likely to use it in trying to
cope with their feelings, it's still important to deal with apathy
whenever it rears its head.
Dealing effectively with apathy
-- or any other emotional problem -- is more difficult when the
underlying problem is masked by a drug. Teenagers who exhibit
such symptoms need help, and drug use may not be their only problem.