By: Lynn Waterhouse, Posted on: April 9, 2014

Why? Because autism is not a single disorder.

March 28, 2014 headline: US Data Shows Autism Rates up 30% to 1 in 68 Children

Yes, prevalence of “autism” is increasing dramatically. But two things are important to keep in mind. First, autism is not one disorder. So it is not one disorder that is being noticed with increased frequency, it is many, many, many, many varied disorders of social behavior development. The Center for Disease Controls March 28, 2014 report of a 30% increase in prevalence is wrong when it states that “Autism spectrum disorder (ASD) is a lifelong developmental disability defined by diagnostic criteria that include deficits in social communication and social interaction and restricted, repetitive patterns of behavior, interests, or activities.” Autism is not one disability; it is hundreds of different genetic and environmental syndromes of developmental social impairment.

Between 200 and 1,000 different gene variants have been found as possible causes for autism syndromes, and between 50 and 100 different pre- and perinatal likely causes for autism syndromes have also been reported. Together these hundreds of different causal syndromes result in many different brain development dysfunctions. What unites these hundreds of different syndromes is that they all result in similar symptoms. The key shared symptom is early childhood social interaction impairment.

A second crucial issue regarding the increasing prevalence of the hundreds of autism social impairment syndromes is that parents, teachers, and professionals are becoming more and more sensitive to many different signs of atypical social development in children. This increased sensitivity causes diagnostic substitution. For children who might previously have been diagnosed as having intellectual disability or severely impaired or delayed language development, the diagnosis of autism is now likely to be substituted. Consequently, it is possible that there is no real increase in the number of children who express atypical social behaviors, such as social withdrawal, extreme social communication impairment, or significant lack of interest in social interaction. It just may be that more children are noticed a having some form of social impairment.

March 26, 2014 headline: Brain Cells that Fail to Mature are Responsible for Autism

On March 26, 2014, researchers reported in The New England Journal of Medicine that they found abnormal brain cell layers and abnormal brain cell connection patterns in two regions of the cerebral cortex of 10 of 11 children with autism who had died. They reported finding similar abnormal brain cell structures in only 1 brain of 11 brains of children who had died without ever having been diagnosed with autism. The researchers concluded that autism is caused by two regions of disorganized patches of brain cells in the cortex.

While this seems at first glance to be a reasonable conclusion, all previously reported findings for brain dysfunction in autism tell us that it is unlikely that autism is caused by two regions of disorganized patches of brain cells in the cortex. For example, 60% of boys with Fragile X syndrome are diagnosed with autism. The Fragile X syndrome leads to protein over production in the brain in many different regions of the cortex and the subcortex. Another example is the Tuberous sclerosis syndrome, in which autism is diagnosed in children who have many varied brain deficits. These deficits include tubers throughout the brain, and abnormal organization of the cerebellum and abnormal patterns of connection from one part of the brain to another. In fact, hundreds of studies over the past twenty years have reported evidence for many varied brain dysfunctions, including bigger brains, smaller brains, a missing connection between the two halves of the cortex of the brain (missing corpus callosum), impairment of the cerebellum of the brain, impairment of the amygdala, impaired axon connections, and impaired gray matter thickness in autism.

There is clear evidence that many different brain dysfunctions exist in autism. Therefore, it cannot be true that autism results from two cortex regions of disorganized brain cell patches. Some cases of autism may result from such patches, however, as noted above, 200 to 1,000 gene variants and 50 and 100 pre- and perinatal disruptions are known to cause hundreds of autism syndromes that, in turn, cause many different brain development dysfunctions.

Remembering that there are hundreds of autism syndromes is important in interpreting new findings.

About Lynn Waterhouse

Dr. Lynn Waterhouse was the Director of Child Behavior Study at The College of New Jersey for 31 years, and is currently a Professor in Global Graduate Programs at the College. NIMH, NICHD, and private funding agencies supported her autism research. She worked with Dr. Lorna Wing on the APA DSM-III-R diagnostic criteria for autism.

Dr. Waterhouse’s book, Rethinking Autism: Variation and Complexity, comprehensively reviews research on autism, and suggests the evidence points toward “autism” being several disorders rather than one, and the implications thereof for finding a cure. Only by ceasing to think of autism as a single disorder can we ever advance research to more accurately parse why these symptoms occur and what the different and varied causes may be. You can save 30% on this book by entering promo code STC3014 at checkout!

April is Autism Awareness Month.