New York, N.Y. -- The changes in brain development that underlie autism spectrum disorder (ASD) may be detectable in children as young as 6 months, according to research reported online today in the American Journal of Psychiatry. While core behaviors associated with ASD (impaired social communication and repetitive behaviors) tend to be identified after a baby's first birthday, researchers found clear differences in brain communication pathways as early as 6 months in infants who later received a definitive diagnosis of ASD.
As part of the Infant Brain Imaging Study (IBIS), senior author Joe Piven, M.D., director of the University of North Carolina's Carolina Institute for Developmental Disabilities in Chapel Hill, and his colleagues studied early brain and behavior development in 92 infants. These infants had older siblings on the autism spectrum and, so, were at elevated risk of developing ASD themselves.
"These results offer promise that we may one day be able to identify infants at risk for autism before the behavioral symptoms are present," says study co-author Geri Dawson, Ph.D., Autism Speaks chief science officer. "The goal," she adds, "is to intervene as early as possible to prevent or reduce the onset of disabling symptoms." One promising area of follow-up research is to identify the specific genetic and biological mechanisms behind the observed differences in brain development.
In their report, the researchers describe using a magnetic resonance imaging technology called diffusion tensor imaging to evaluate the brains of infants at 6 months, 1 year and 2 years of age. This allowed them to create three-dimensional pictures showing changes over time in each infant's "white matter." White matter represents the part of the brain that is particularly rich in the nerve fibers that form major information pathways between different brain regions.
The 28 infants who went on to develop ASD showed different white matter development for 12 of the 15 major brain pathways studied compared with 64 infants who did not go on to develop ASD. At 6 months, there was evidence that the white matter fiber tracts were different in infants who later developed ASD from those of infant siblings who did not develop ASD, and over time it appears that there is a slowing in white matter development. It is a brain marker that differs in children who go on to be classified with autism. These developmental differences may suggest slower white matter development during early childhood, when the brain is making and strengthening vital connections.
"It's too early to tell whether the brain imaging techniques used in the study will be useful in identifying children at risk for ASD in early infancy," Piven says. "But the results could guide the development of better tools for predicting the risk that a child will develop ASD and perhaps measuring whether early intervention therapies improve underlying brain biology."
This work was supported by grants from the National Institutes of Child Health and Development, Autism Speaks and the Simons Foundation. Further support was provided by the National Alliance for Medical Image Computing, funded by a National Institute of Biomedical Imaging and Bioengineering grant. With funding from Autism Speaks, the IBIS team is also looking at the genetic and environmental influences on brain and behavior development in these high-risk infants.
Autism is a general term used to describe a group of complex developmental brain disorders - autism spectrum disorders - caused by a combination of genes and environmental influences. These disorders are characterized, in varying degrees, by social and behavioral challenges, as well as repetitive behaviors. An estimated 1 in 110 children in the U.S. is on the autism spectrum - a 600 percent increase in the past two decades that is only partly explained by improved diagnosis.
About Autism Speaks
Autism Speaks is the world's leading autism science and advocacy organization. Since its inception in 2005, Autism Speaks has made enormous strides, committing over $173 million to research and developing innovative resources for families. The organization is dedicated to funding research into the causes, prevention, treatments and a cure for autism; increasing awareness of autism spectrum disorders; and advocating for the needs of individuals with autism and their families. In addition to funding research, Autism Speaks has created resources and programs including the Autism Speaks Autism Treatment Network, Autism Speaks' Autism Genetic Resource Exchange and several other scientific and clinical programs. Notable awareness initiatives include the establishment of the annual United Nations-sanctioned World Autism Awareness Day on April 2, which Autism Speaks celebrates through its Light it Up Blue initiative. Also, Autism Speaks award-winning "Learn the Signs" campaign with the Ad Council has received over $316 million in donated media. Autism Speaks' family resources include the Autism Video Glossary, a 100 Day Kit for newly-diagnosed families, a School Community Tool Kit, a Grandparent's Guide to Autism, and a community grant program. Autism Speaks has played a critical role in securing federal legislation to advance the government's response to autism, and has successfully advocated for insurance reform to cover behavioral treatments in 29 states thus far, with legislation continuing to advance in more states. Each year Walk Now for Autism Speaks events are held in more than 85 cities across North America. To learn more about Autism Speaks, please visit www.autismspeaks.org.
About the Co-Founders
Autism Speaks was founded in February 2005 by Suzanne and Bob Wright, the grandparents of a child with autism. Bob Wright is Senior Advisor at Lee Equity Partners and Chairman and CEO of the Palm Beach Civic Association. He served as Vice Chairman of General Electric; and as the Chief Executive Officer of NBC and NBC Universal for more than twenty years and is a graduate of the College of Holy Cross and the University of Virginia School of Law. He also serves on the board of directors of the Polo Ralph Lauren Corporation, Mission Product, EMI Group Global Ltd., and AMC Networks Inc., and is a Trustee of the New York Presbyterian hospital. Suzanne Wright is a Trustee Emeritus of Sarah Lawrence College, her alma mater. Suzanne has received numerous awards, the Women of Distinction Award from Palm Beach Atlantic University, the CHILD Magazine Children's Champions Award, Luella Bennack Volunteer Award, Spirit of Achievement award by the Albert Einstein College of Medicine's National Women's Division and The Women of Vision Award from the Weizmann Institute of Science. In 2008, the Wrights were named to the Time 100 Heroes and Pioneers category, a list of the most influential people in the world, for their commitment to global autism advocacy. They have also received the first ever Double Helix Award for Corporate Leadership from Cold Spring Harbor Laboratory, the NYU Child Advocacy Award, the Castle Connolly National Health Leadership Award and the American Ireland Fund Humanitarian Award. In the past couple of years the Wrights have received honorary doctorate degrees from St. John's University, St. Joseph's University and UMass Medical School.