Meth
and the Brain
by
Stacey Young
It's
long been said that drug use harms your brain, but researchers
using scans of the brain are now learning just exactly
how bad that damage really is. This ScienCentral News
video has more.
Addiction
Blues
The
poetry in Lee L.'s voice as he describes his great love
is hypnotic.
"I
loved Crystal," he gushes. Lee's not speaking of a person,
but methamphetamine, known by its street name, Crystal
Meth. "It gave me a sense of power. It made me feel
hungry. It made me feel sexual. It made me feel virile.
It was like all of the switches in my body and in my brain
felt like they finally got turned on."
Lee—a
42-year-old composer who asked that his last name not
be used in keeping with his involvement in the twelve-step
program, New York Crystal Meth Anonymous—hunted
down the drug as the days dragged between runs, even though
he knew it was doing considerable bodily damage. "The
physical body collapses a little every time, certainly
in my case, every time that I used," he recalls. "The
reward that it got was it hit upon a pleasure center in
the brain."
For
the first time, scientists have seen exactly which brain
areas in the recovering methamphetamine addict change
in the immediate days after they begin recovery. Edythe London, a neuroscientist at the University of California at Los Angeles, along with
her colleagues, used PET scans—or positron emission tomography—to image how glucose
is processed in the brains of 17 methamphetamine abusers
who had stopped using the drug nearly a week before they
participated in her study. She then compared those brain
images with the brain images of 18 non-abusers, who completed
the same attention task as their brains were measured.
"When
people take crystal meth and become dependent on the drug,
there is a real change in how the brain works," she says.
"Very specifically, those circuits in the brain that are
primarily in the pre-frontal cortex
are down-regulated." The pre-frontal cortex is responsible
for controlling behavior, but it also regulates an area
in the lower brain—the amygdala—responsible
for emotion. "The methamphetamine abuser, at least in
early abstinence, has a pre-frontal cortex that's not
doing its job of controlling the amygdala. So when the
methamphetamine user is reminded of drug taking by being
in a place where he or she took the drug before…or even
the feeling of money in the pocket that could be used
to take the drug, this turns on the amygdala and other
areas of the brain that are important for craving."
Coupled
with cranked-up craving is another danger, a huge complaint
methamphetamine abusers have as they try to navigate the
waters of abstinence: A depression so crushing the alternative—more
methamphetamine—seems preferable. "There's an incredible
manic high that's followed by this depression that feels
like it's ripping me apart," Lee L. says.
This
jumbled biochemical process helps explain in part why
chronic crystal users have such a difficult time quitting,
London says: "This really can color how they feel and
make them want to take the drug again."
Worldwide,
crystal meth use has reached epidemic proportions, London
says. "Really, meth is the largest abused drug after marijuana
and the effects of meth are very long-lasting and very
remarkable in terms of brain function. Kids that use meth
have no idea what they're getting into."
National Institutes of Health figures show that,
for now, crystal meth use amongst teens stabilized in
2003 at 6.2 percent of high school seniors who reported
use of methamphetamine, unchanged from 6.9 percent in
2001. All told, 12.4 million Americans age 12 and older—or
5.3 percent of the population—had tried methamphetamine
at least once by 2002, the National Survey on Drug Use
and Health reported on the same NIH website.
With
London's contribution, treating addicts may soon change.
They'll possibly get anti-depressants during the initial
phases of treatment to get them over the depression hump.
The new information "is absolutely critical," London says,
if doctors want to "tailor make therapies for this brain
as it changes and approaches recovery."
Lee
L. won't say that he'll never do the drug again. Instead,
he's taking it one day at a time, and says that since
he's been off crystal meth, he's never experienced so
much peace.
This
research appeared in the February, 2004 issue of the American Journal
of Psychiatry, and was funded by the National Institute on
Drug Abuse.
Original source: http://www.sciencentral.com