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From
The
National Institute on Drug Abuse, a component of the National
Institutes of Health, U.S. Department of Health and Human Services
Results of a new
study indicate that people who have recently stopped abusing the
powerfully addictive drug methamphetamine may have brain abnormalities
similar to those seen in people with mood disorders. The findings suggest
practitioners could improve success rates for methamphetamine users
receiving addiction treatment by also providing therapy for depression and
anxiety in appropriate individuals. The study is published in the January
2004 issue of the journal Archives of General Psychiatry.
“Methamphetamine
abuse is a grave problem that can lead to serious health conditions
including brain damage, memory loss, psychotic-like behavior, heart
damage, hepatitis, and HIV transmission,” says Dr. Nora D. Volkow,
director of the National Institute on Drug Abuse (NIDA), National
Institutes of Health, which funded the study. “Currently, no medication
exists to treat abuse or addiction to amphetamines or amphetamine-like
compounds; however, drug counselors and other health professionals have
successfully used behavioral interventions to treat addiction. Treatment
outcomes may improve if associated mental conditions are addressed
concurrently with addiction.”
Dr. Edythe London
and her colleagues at the University of California Los Angeles, the
University of California Irvine, and NIDA’s Intramural Research Program
used positron emission tomography — PET, a technology to image brain
activity — to compare glucose metabolism in the brains of 17
methamphetamine abusers who had stopped using the drug 4–7 days before
their participation in the study, and 18 non-abusers. The methamphetamine
abusers averaged a 10-year history of drug abuse that included consuming
an average of 4 grams of methamphetamine per week. They said they had used
the drug at least 18 of the preceding 30 days.
All participants
responded to questions about their drug use, and underwent a PET scan to
measure how their brains used glucose while they performed an attention
task. On the day of the scan, participants rated their symptoms of
depression and anxiety. The methamphetamine abusers also rated their
cravings for the drug within 48 hours of the scan. The scientists found
that methamphetamine abusers reported higher ratings of depression and
anxiety than non-abusers.
The PET scans
showed that the two groups exhibited significant differences in glucose
metabolism in specific brain regions. In methamphetamine abusers, glucose
metabolism was lower in brain regions linked to depressive disorders,
depressed mood, and sadness. It was higher in brain regions linked to
anxiety and drug cravings.
“Improving our
awareness of substance abuse as a condition that does not exist in
isolation will contribute to more effective prevention and treatment
interventions,” says Dr. Volkow. |
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