Autism rates continue to rise

 I was shocked to learn that about 1 in 44 children has been identified with autism spectrum disorder. The statistics come from data collected in 2018 by the CDC and recently analyzed. The report focused on the prevalence of autism among eight-year-olds. In 2009, the CDC’s data showed the number to be 1 in 110. That is a shocking increase. I remember when nobody had ever heard of autism. It seems like not that long ago. The disorder was first described in 1943 by a psychiatrist at Johns Hopkins who found eleven children with what he called a unique condition. (By the way, this was well before vaccines were commonplace. The idea that autism is caused by the MMR vaccine has been thoroughly refuted by studies all over the world.) 

The latest thinking is that the disorder is caused by a malfunctioning immune system, either because of infections acquired by the pregnant mother, or acquired by the child after birth, or both. Andrew Zimmerman, a scientist working at Johns Hopkins, found that brain tissue from deceased autistic people showed dramatic evidence of inflammation (the brain has it own resident immune cells). When checking the spinal fluid from living autistic people, he also observed markers of inflammation. Betty Diamond, head at the Center for Autoimmune and Musculoskeletal Diseases at The Feinstein Institutes for Medical research notes, “The immune system must be understood, not just as a defense against microbial invasion, but also as a sensory organ that informs the brain.” 

What’s more, as I discussed in an earlier post, children with autism have lower diversity of microbiota in their intestines as well as a nearly-depleted strains of helpful bacteria—conditions that can affect brain development. Kevin Becker, a geneticist at the National Institutes of Health says, “Something environmental is causing the rise, and it seems to parallel asthma and autoimmunity,” which is also on the rise. Broadly speaking, autism follows the same epidemiological patterns as asthma. One bit of data: if a mother has an autoimmune disorder, the chances of her child having autism increased nearly nine-fold.

This is an enormously complicated subject. Basically, it appears that the rise in autism is caused by inappropriate inflammation which in turn, some think, is caused by “environmental factors.”  No one really knows what those environmental factors might be.

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