Friday, March 28, 2014

Autism on the Brain (Literally)

Two new autism studies out this week. One shows brain abnormalities among children with autism. The other, rising rates of autism. Before you get too excited about either one, take a closer look.

The first, a post-mortem examination of brain tissue in children who'd been diagnosed with autism landed in the New England Journal of Medicine but don't be too terribly impressed just yet. It included a mere 22 kids, half with autism, half without. Researchers found similar rough "patches" in the top cortical layer of 10 of the 11 children with autism suggesting something went wrong during cortical development which happens early in the prenatal period. This no doubt valuable study suggests pregnancy is a critical time for the development of autism.

The media, however, generally declared it incontrovertible evidence.

Researchers have published a study that gives clear and direct new evidence that autism begins during pregnancy. Science Daily 
Study: Autism Starts in Pregnancy UPI
Autism Begins as Brain Cells Altered in Womb, Study Finds Bloomberg

Some outlets fortunately summoned some constraint in their headlines and more nuance in the articles (faint!).

Brain Changes Suggest Autism Starts In The Womb NPR 
Autism May Originate During Pregnancy, Study Says Fox News 

The media often didn't attempt to explain why this study isn’t conclusive evidence that autism starts in pregnancy or that it stems from these cortical disruptions. At this point, it's not clear how these rough spots might be linked to autism. They might not be responsible for the numerous symptoms associated with the disorder. They could be a result of other changes or abnormalities related to autism.*

Now for the CDC report. Here's the news in brief: 

Autism rose almost 30% between 2008 and 2010. Since 2000 rates have more than doubled. Take a look at the numbers:

1 in 88 kids "autistic" (2008)
1 in 68 kids "autistic" (2010)

Few media outlets bothered to highlight or even mention one of the most striking aspects of this study. Who those 1 in 68 included -  children without official autism diagnoses. Researchers scoured medical and school records for signs of autism including autistic-like symptoms/behavior. The last few national estimates have employed this same wide net, so remember this every time you read about rising autism. 

CNN was the only major media source I could find that quoted an expert who was concerned about the inclusion of children that might not have autism:
"This report tells us that there's a significant number of children in the states where they were assessed that have social differences and a pattern of behaviors that can be represented by ASD, but may also be due to other conditions that superficially can have similar features, such as social anxiety, ADHD with social immaturity and intelligence problems," [Dr. Max Wiznitzer, pediatric neurologist at Rainbow Babies and Children's Hospital in Cleveland] says. 
Is it any wonder autism appears to be rising? Not to the experts. 
Despite their concern, experts said they were not surprised by the increase, because other data had suggested the numbers would continue to climb. In New Jersey, for instance, autism rates were 50% higher than in the rest of the nation in 2000, and they remained that much higher in 2010 – suggesting the national rates will continue to rise to catch up, said Walter Zahorodny, a psychologist who directs the New Jersey Autism Study. "To me it seems like autism prevalence can only get higher," he said. USA Today


For now I'll disregard the possibility Walter might have a vested interest in seeing those numbers soar. I will also ignore his comment that racial discrepancies in diagnoses might reflect true differences in incidence of autism and not other factors (e.g., access to health care). As a mother who gestated and birthed three babies in Jersey, I am interested in these autism numbers:

1 in 45 kids in New Jersey

1 in 175 kids in Alabama

1 in 42 boys, 1 in 189 girls

New Jersey is the only state to find all the children with autism? The rest of the country should catch up with them? I'm not sure anybody should be holding up New Jersey as an example of accurate autism assessment. One has to wonder whether the state might be stretching the diagnosis a bit.

Questions remain, duh. Chief among them is whether the actual incidence of autism increasing. It's not clear at all to what extent expanded criteria (both in the DSM and national incidence rates) have contributed to rising rates of autism. 

The Washington Post, for one, isn't so convinced these numbers reflect a true rise in autism:

“We can’t dismiss the numbers. But we can’t interpret it to mean more people are getting the disorder,” said Marisela Huerta, a psychologist at the New York-Presbyterian Center for Autism and the Developing Brain in suburban White Plains, N.Y.
Sure the media sought out the usual autism experts and advocacy organizations this week, including the omnipresent Autism Speaks. But I only came across one that quoted Alison Singer, the co-founder and president of the Autism Science Foundation, the one that never championed the harmful vaccine theory. Singer, who has a severely autistic child, attributes the rise in autism to more high-functioning kids getting the diagnosis: 

“The likelihood of a child having an autism record is higher, but that’s not because more of them have it,” says Singer. “The community health care providers are more likely to diagnose a child with autism than they would have been in previous years. There is more awareness of the disorder and that you don’t need to have an intellectual disability [to have ASD].” The Daily Beas

She worries that autism is now more recognized as a social disorder, a more mild set of symptoms instead of one of with more profound deficits in speech and intellectual abilities, also repetitive, sometimes self-injurious behavior. She worries that kids with more classic autism will be deprived of resources and research attention.


But that doesn’t play nearly as well in the media as that 1 in 68 kids!

*UPDATE: Check out this great analysis of the relative risks of factors related to autism. Sam Wang at Princeton wrote it and the New York Times published it. Why hasn't anyone done this before? 

1 comment:

Media Mentions said...

One possibility that isn't getting enough attention is overdiagnosis. Autism isn't a black and white condition: it's a spectrum, so kind of like the case with ADHD, there may be a grey area here as well. From what I read in the press today, only one article brings up this argument: http://www.pressreader.com/bookmark/HBRCHVPQ78V/TextView and I think it's one that's worth a look.