Meth use and HIV
combine to cause brain impairment

A study in the August issue of the American Journal of Psychiatry suggests that methamphetamine use and HIV infection might work together to cause significant changes to the brain's structure and lead to cognitive function impairments, CQ HealthBeat reports. Researchers at the University of California, San Diego, studied brain scans of 103 adults--including HIV-positive and HIV-negative meth users--and also gave all study subjects cognitive function tests to gauge such processes as memory, information processing speed, verbal functioning, and motor functioning.

The study found that both meth use and HIV infection independently affect brain function, but the two together cause significant cognitive impairment. Meth use was shown to increase the volume of the brain's parietal cortex, which affected the study subjects' ability to pay attention to their surroundings, and the basal ganglia, which control motor function and motivation. HIV was shown to decrease brain volume in the cerebral cortex, which is associated with reasoning and memory; in the hippocampus, which is linked with learning and memory; and in the basal ganglia.