A new study finds children with autism spectrum disorder (ASD) experience a distinct chemical change in their brain that contribute to developmental delays, according to a University of Washington news release.

"Between ages three and 10, children with autism spectrum disorder exhibit distinct brain chemical changes that differ from children with developmental delays and those with typical development," the University said.

The findings were published in the Journal of the American Medical Assocation Psychiatry.  According to the researchers, the findings give new insight that may improve early detection and intervention.

"In autism, we found a pattern of early chemical alterations at the cellular level that over time resolved - a pattern similar to what others have seen with people who have had a closed head injury and then got better," said Stephen R. Dager, a UW professor of radiology and adjunct professor of bioengineering and associate director of UW's Center on Human Development and Disability, in the news release. 

"The brain developmental abnormalities we observed in the children with autism are dynamic, not static. These early chemical alterations may hold clues as to specific processes at play in the disorder and, even more exciting, these changes may hold clues to reversing these processes."

Researchers compared brain chemistry among three groups of children in the study: children who had ASD, children with a diagnosed developmental delay, and kids who were considered to be developing normally.  A magnetic resonance spectroscopic imaging, a type of MRI, was used to measure tissue-based chemicals in three age groups: 3-4 years, 6-7 years and 9-10 years.

N-acetylaspartate (NAA) was a brain chemical measured in the study.  According to the news release, it is believed to be an important aspect of "regulating synaptic connections and myelination." Levels of NAA decreased in people with conditions like Alzheimer's, traumatic brain injury or stroke.

The researchers found scans of 3- to 4-year-olds showed lower levels of NAA in both the ASD and developmentally delayed groups. When the kids were 9 to 10 years, NAA levels in children diagnosed with ASD had caught up to the levels of the typically developing group, but low levels of NAA were found in the developmentally delayed.

"A substantial number of kids with early, severe autism symptoms make tremendous improvements. We're only measuring part of the iceberg, but this is a glimmer that we might be able to find a more specific period of vulnerability that we can measure and learn how to do something more proactively," Annette Estes, a co-author of the study and director of the UW Autism Center, stated in the news release.