New research published indicates that methamphetamine abuse and HIV infection cause significant alterations in the size of certain brain structures, and in both cases the changes may be associated with impaired cognitive functions, such as difficulties in learning new information, solving problems, maintaining attention and quickly processing information.

Co-occurring methamphetamine abuse and HIV infection appears to result in greater impairment than each condition alone.

"Methamphetamine abuse is linked with HIV, hepatitis C, and other sexually transmitted diseases, not only by the use of contaminated injection equipment, but also due to increased risky sexual behaviors," says Dr. Nora D. Volkow, director of the National Institute on Drug Abuse (NIDA), National Institutes of Health, which helped support the research. "These findings show that methamphetamine abuse and HIV infection each cause significant
changes in the volume of brain gray matter structures and cognitive function."

Changes seen in brain structures could be the result of inflammation in the brain and/or compensatory changes associated with methamphetamine toxicity. Also, brain inflammation associated with HIV infection may contribute to brain cell shrinkage or loss.

Dr. Volkow says medications that reduce inflammation might be useful in treating methamphetamine abusers.

"The effects of methamphetamine and HIV on the brain are distinct but may affect the same brain regions, so understanding how the underlying mechanisms interact also may lead to more effective therapies and the information should be useful in guiding future studies," Dr. Volkow
concludes.

For more information, visit http://www.nih.gov/news/pr/aug2005/nida-11.htm>.