Director’s Blog: Autism Awareness: April 2014
By Thomas Insel on
Autism Awareness Month arrives this year with a package of new, important research findings. Below I describe a few of these. The field is moving so rapidly that, by the end of April, there will likely be yet a new crop of findings—so this is, at best, a progress report for the beginning of Autism Awareness Month.
Today the Centers for Disease Control and Prevention (CDC) released new numbers on the prevalence of autism, based on the most recent results from their long running Autism and Developmental Disabilities Monitoring (ADDM) network. Looking at administrative data on 8-year-olds from 11 sites across the country, ADDM reported a prevalence of autism of 1 in 68 children in 2010 (based on children born in 2002), up from 1 in 88 in 2008 (based on children born in 2000). There was considerable variation across the 11 sites: from 1 in 45 in New Jersey to 1 in 175 in Alabama. As in previous surveys, boys were almost 5 times more likely to have an autism label. The prevalence in boys was 1 in 42; in girls, 1 in 189.
One of the best things about the ADDM network is that it has provided surveillance using similar methods for over a decade. The prevalence of autism as estimated from administrative records has increased: by 125 percent since 2002 and by 29 percent just between 2008 and 2010. How much of this increase is “more detected” versus “more affected”? Is this increase a mark of better care, with more cases identified and treated, or is this a reflection of a continually growing public health care emergency due to more children affected? ADDM cannot answer these questions, but it does point to the need for a population-wide study, as currently planned by CDC and Autism Speaks in South Carolina. A previous total population study of all 7- to12-year-olds in a town in South Korea (more than 55,000 children) used standardized diagnostic instruments for children who screened positive and reported a prevalence of 1 in 38 children. Could that figure, which is in the range of the ADDM estimate of 1 In 45 for New Jersey, serve as a reasonable estimate for the actual prevalence once everyone with autism is detected? Perhaps the ADDM numbers will continue to rise, indicating better detection as awareness of the signs and symptoms increase.
Whatever the meaning of the new ADDM report, there is little doubt that more children and more adults on the autism spectrum will require more services. Ganz estimated the lifetime economic cost of autism to be $3.2 million per individual, back in 2006 when the prevalence was thought to be closer to 1 in 150.1 A new economic analysis looks at the cost, including education and indirect costs, based on three national data sets.2 The additional cost of having a child with autism was $17,081 per year in 2011. Only 18 percent of these costs were related to health care; half were attributed to school costs. Assuming 673,000 children ages 3 to 17 with a diagnosis of autism spectrum disorder, the total societal cost would be roughly $11.5 billion per year. Of course, with new estimates from the CDC about the increase in prevalence, these costs may need to be adjusted upward.
On the brain research front, a new report in the New England Journal of Medicine describes changes seen in the architecture of post-mortem brains in 10 of 11 children who had an autism diagnosis.3 Similar changes were found in only 1 of 11 unaffected children. Dr. Eric Courchesne and his colleagues at the University of California, San Diego and Dr. Ed Lein and colleagues at the Allen Institute of Brain Science found patches of abnormal anatomy in parts of the brain associated with social and communication functions. Given that the pattern of cell layers in the cortex is laid down prenatally, these findings, if replicated, suggest that brain changes in autism are likely to have originated before birth, although the disorder is usually diagnosed behaviorally after age 4 years.
In 2014, the mystery of autism remains largely unsolved. We describe autism as a neurodevelopmental disorder, but even with the new report mentioned above, we do not know precisely how to define what the brain disorder is or when it occurs. We realize that as many as 30 percent of children with autism have spontaneous genetic mutations, but these large genetic changes have not yet been shown to cause the disorder, since other children with some of the same changes don’t have autism. We have treatments for autistic symptoms, helping many children to enter regular classrooms and ultimately function fully in society. But these behavioral treatments are expensive and intensive and often not available to children in need. Medical treatments have lagged behind.
All of this reminds us that for both children and adults with autism we need more science as well as more services. Indeed, the best way to better services will be through better science. As we understand what happens in the developing brain that renders a child unable to communicate or unable to engage the social world, we will be better able to provide earlier detection and better interventions. As we identify the many forms of autism, some more genetic, some more environmental, we can expect better tools for prevention and treatment. And as we understand better the evolution of autism in adults, we should be able to provide better care and offer better outcomes. Autism awareness reminds us of the vital importance of committing to both science and service for an increasing number of our fellow citizens.
1 Ganz ML. The lifetime distribution of the incremental societal costs of autism. Arch Pediatr Adolesc Med. 2007 Apr;161(4):343-9.
2 Lavelle TA et al. Economic burden of childhood autism spectrum disorders. Pediatrics. 2014 Mar;133(3):e520-9. doi: 10.1542/peds.2013-0763. Epub 2014 Feb 10.