DRUGS THREATEN TEENS' BRAINS

Can Change Wiring In Head

ST. LOUIS - Teenagers who drink, smoke and use drugs can derail their
brain development and set themselves up for lifelong addiction.

And parents who strictly monitor their teens' behavior are one of the
most influential forces preventing kids from using drugs and alcohol.

Now that might not sound like news to you, but truth is, until
recently most of what science has known about addiction in teenagers
has been extrapolated from research in adults. Now, new brain-imaging
studies have shown that the teenage brain is a rapidly changing organ
and doesn't work the way an adult brain does. Researchers now believe
that drugs and alcohol can disrupt that massive renovation of the
brain during adolescence, making it more vulnerable to drugs and
easier for teens to get addicted.

And scientists say that an addiction that starts early in life is
harder to kick than one that starts later. Nearly half of kids who
are regular drinkers before age 14 will become alcoholics, said Dr.
Danielle Dick, a clinical psychologist and geneticist at Washington
University. That puts early drinkers at three times greater risk of
alcohol addiction than people who wait until age 21 to start
drinking, she said.

Vulnerable age group: Epidemiological studies have shown that most
addictions start in adolescence, said Dr. Nora Volkow, director of
the National Institute on Drug Abuse. And when a teenager's
pleasure-chemical systems aren't fully developed and then get wired
to depend on substances for feeling good, the normal flow of brain
chemicals that aid in learning, decision making and other key
processes are often blocked, Volkow said.

In adults, genetics are more than 50 percent responsible for
addiction to alcohol. So people have long assumed that genes are the
biggest reason kids drink, too.

But new studies of twins in Finland and Missouri showed no evidence
that genetics contributed to alcohol-dependence in 14-year-olds, Dick said.

Take action, parents: Instead, Dick said, parental monitoring is one
of the most consistent predictors of whether teens start using
alcohol and other drugs.

That means more than just having a good relationship with your kids.
A good, warm relationship doesn't mean kids are going to tell parents
what they are doing, or with whom.

"Parents might say, 'Oh, if they were doing that, they'd tell me,'
but the reality is, they probably won't," Dick said. What works is
knowing where children are, who they are with and what they are
doing. Children with the highest level of parental monitoring were
less likely to start drinking or using drugs, Dick said.

For an addiction to take hold, kids must be exposed to addictive
substances. So young adolescents who never have a chance to smoke or
drink avoid stirring up a genetic predisposition to addiction. In a
more permissive environment, genes may rear their heads.

Marijuana: Once teens start to drink or use drugs, the consequences
turn severe. Recent studies show that teens who start using marijuana
before they turn 17 are at higher risk of developing schizophrenia
than people who didn't use or started smoking marijuana later in
adolescence or young adulthood.

Marijuana has often been called a gateway drug, a substance that can
lead to use of more harmful drugs. Most researchers agree that
marijuana doesn't necessarily set up the brain for further
addictions, but does give kids practice in obtaining illicit
substances and access to a subculture where harder drugs are available.

Nicotine: The real gateway drug might be nicotine, experts say. Most
kids try cigarettes before other drugs.

Researchers compared sets of identical twins in which one twin
started smoking before age 17 and the other twin smoked later. Twins
who started smoking before age 17 became addicted to other
substances, such as alcohol or other drugs, more readily than their
twins who waited, Volkow said. Because identical twins have the same
genetic make-up, the addiction of early-smoking twins can't be
chalked up to genetic susceptibility alone, she said.

Cigarette smoking also can disrupt memory and attention, said Dr.
Leslie Jacobsen, a psychiatrist at Yale University. But withdrawal
from cigarettes is also bad, she said.

"Once you're dependent, you're always confronted with a certain
amount of nicotine withdrawal," she said.

"Children get addicted to smoking more quickly than they expect, and
many aren't even aware that they are dependent," she said.

Binge drinking: Even teens who just binge drink on weekends can hurt
their brains, said Susan F. Tapert, an associate professor of
psychiatry at the University of California, San Diego. Her
measurements of a seahorse-shaped part of the brain, called the
hippocampus, revealed that drinkers had shrunken hippocampuses
compared with teens who don't drink. That is important because the
hippocampus is one of the regions of the brain most responsible for
learning and memory.

Tapert doesn't see the same dramatic change in the hippocampus of
marijuana smokers.

But that may not matter, Jacobsen said.

"It's not just how the brain looks, but how it works that's
important," she said.

Teens who smoke marijuana - even those who have stopped using for a
month - need to expend much more mental energy to do simple tasks, Tapert said.

For instance, marijuana smokers retain 5 percent to 10 percent less
information when listening to a story. That difference may not seem
big, but could make the difference between passing or failing a test in school.