Pubdate: Mon, 03 Apr 2006
Source: Aberdeen American News (SD)
Copyright: 2006 Aberdeen American News
Contact:  http://www.aberdeennews.com/mld/aberdeennews/
Details: http://www.mapinc.org/media/1484
Author: Tina Hesman Saey, Knight Ridder
Bookmark: http://www.mapinc.org/youth.htm (Youth)

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.
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MAP posted-by: Beth Wehrman