Feb. 17, 2012 -- Differences in brain development may be evident as early as age 6 months in children who go on to develop autism, according to new research.

In the study, children later diagnosed with autism spectrum disorder (ASD) had abnormal development of the white matter in the brain, says researcher Joe Piven, MD, director of the Carolina Institute for Developmental Disabilities at the University of North Carolina, Chapel Hill.

White matter is rich in nerve fibers. It is crucial so the regions of the brain can ''talk'' to each other. This study has found the earliest brain differences in autism, Piven believes.

"There is an aberrant pattern related to autism," he tells WebMD.

"As early as 6 months, the brain of a child who develops autism is organizing itself differently," says researcher Jason Wolff, PhD, a University of North Carolina postdoctoral fellow.

The study is published in the American Journal of Psychiatry.

Autism spectrum disorders are complex developmental brain disorders. ASDs now affect one in 110 U.S. children, according to the CDC. Genetic and environmental factors are blamed. People with the condition have social and behavioral challenges and repetitive behaviors.

Researchers are trying to find early clues of ASD, before symptoms develop.