Brain damage linked to prenatal meth exposure

A developing fetus exposed to methamphetamine can cause far more damaging brain, cognitive and behavioral problems than prenatal exposure to alcohol, a study said Tuesday.

University of California Los Angeles professor Elizabeth Sowell and her colleagues used structural magnetic resonance imaging (sMRI) to evaluate the specific effects of prenatal meth-exposure by comparing the brain scans of 61 children.

Among the participating children, 21 had prenatal meth and alcohol exposure, 13 had heavy alcohol exposure only and 27 were not exposed to either meth or alcohol.

The scientists showed for the first time that children whose mothers consumed meth during pregnancy - with or without alcohol - had structural abnormalities in the brain that were more severe than those seen in children whose mothers abused alcohol alone.

They found that the caudate nucleus, a structure important for learning and memory, motor control and motivation, was one of the brain regions more reduced by meth than alcohol exposure.

Earlier studies have shown that alcohol-exposed children have some smaller brain structures. Sowell and her colleagues found the affected brain regions were similar for meth-exposed children, with some of the brain regions even smaller and others larger than normal.

The larger volume in meth-exposed children was found in the cingulate cortex, an area linked to control and conflict resolution.

Based on brain images and IQ information, researchers were also able to chart a child's past exposure to drugs.

The scientists noted that detailed data about vulnerable brain structures could eventually help diagnose children with cognitive or behavioral problems who do not have a well-documented history of drug exposure.

"We know that alcohol exposure is toxic to the developing fetus and can result in lifelong brain, cognitive and behavioral problems," said Sowell, whose study appears in Wednesday's issue of The Journal of Neuroscience.

"In this study, we show that the effects of prenatal meth exposure, or the combination of meth and alcohol exposure, may actually be worse. Our findings stress the importance of drug abuse treatment for pregnant women."

Among the over 16 million Americans older than 12 who have used meth, some 19,000 are pregnant women, according to the National Survey on Drug Use and Health.

About half of women who said they used meth while pregnant also consumed alcohol.