Why Are Autism Rates Steadily Rising?
Stefania Sterling was just 21 when she had her son, Charlie. She was young and healthy, with no genetic issues apparent in either her or her husband's family, so she expected Charlie to be typical.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period."
It wasn't until she went to a Mommy and Me music class when he was one, and she saw all the other one-year-olds walking, that she realized how different her son was. He could barely crawl, didn't speak, and made no eye contact. By the time he was three, he was diagnosed as being on the lower functioning end of the autism spectrum.
She isn't sure why it happened – and researchers, too, are still trying to understand the basis of the complex condition. Studies suggest that genes can act together with influences from the environment to affect development in ways that lead to Autism Spectrum Disorder (ASD). But rates of ASD are rising dramatically, making the need to figure out why it's happening all the more urgent.
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Indeed, the CDC's latest autism report, released last week, which uses 2016 data, found that the prevalence of ASD in four-year-old children was one in 64 children, or 15.6 affected children per 1,000. That's more than the 14.1 rate they found in 2014, for the 11 states included in the study. New Jersey, as in years past, was the highest, with 25.3 per 1,000, compared to Missouri, which had just 8.8 per 1,000.
The rate for eight-year-olds had risen as well. Researchers found the ASD prevalence nationwide was 18.5 per 1,000, or one in 54, about 10 percent higher than the 16.8 rate found in 2014. New Jersey, again, was the highest, at one in 32 kids, compared to Colorado, which had the lowest rate, at one in 76 kids. For New Jersey, that's a 175 percent rise from the baseline number taken in 2000, when the state had just one in 101 kids.
"It is surprising that the prevalence of a significant disorder like autism has risen so consistently over a relatively brief period," said Walter Zahorodny, an associate professor of pediatrics at Rutgers New Jersey Medical School, who was involved in collecting the data.
The study echoed the findings of a surprising 2011 study in South Korea that found 1 in every 38 students had ASD. That was the the first comprehensive study of autism prevalence using a total population sample: A team of investigators from the U.S., South Korea, and Canada looked at 55,000 children ages 7 to 12 living in a community in South Korea and found that 2.64 percent of them had some level of autism.
Searching for Answers
Scientists can't put their finger on why rates are rising. Some say it's better diagnosis. That is, it's not that more people have autism. It's that we're better at detecting it. Others attribute it to changes in the diagnostic criteria. Specifically, the May 2013 update of the Diagnostic and Statistical Manual of Mental Disorders-5 -- the standard classification of mental disorders -- removed the communication deficit from the autism definition, which made more children fall under that category. Cynical observers believe physicians and therapists are handing out the diagnosis more freely to allow access to services available only to children with autism, but that are also effective for other children.
Alycia Halladay, chief science officer for the Autism Science Foundation in New York, said she wishes there were just one answer, but there's not. While she believes the rising ASD numbers are due in part to factors like better diagnosis and a change in the definition, she does not believe that accounts for the entire rise in prevalence. As for the high numbers in New Jersey, she said the state has always had a higher prevalence of autism compared to other states. It is also one of the few states that does a good job at recording cases of autism in its educational records, meaning that children in New Jersey are more likely to be counted compared to kids in other states.
"Not every state is as good as New Jersey," she said. "That accounts for some of the difference compared to elsewhere, but we don't know if it's all of the difference in prevalence, or most of it, or what."
"What we do know is that vaccinations do not cause autism."
There is simply no defined proven reason for these increases, said Scott Badesch, outgoing president and CEO of the Autism Society of America.
"There are suggestions that it is based on better diagnosis, but there are also suggestions that the incidence of autism is in fact increasing due to reasons that have yet been determined," he said, adding, "What we do know is that vaccinations do not cause autism."
Zahorodny, the pediatrics professor, believes something is going on beyond better detection or evolving definitions.
"Changes in awareness and shifts in how children are identified or diagnosed are relevant, but they only take you so far in accounting for an increase of this magnitude," he said. "We don't know what is driving the surge in autism recorded by the ADDM Network and others."
He suggested that the increase in prevalence could be due to non-genetic environmental triggers or risk factors we do not yet know about, citing possibilities including parental age, prematurity, low birth rate, multiplicity, breech presentation, or C-section delivery. It may not be one, but rather several factors combined, he said.
"Increases in ASD prevalence have affected the whole population, so the triggers or risks must be very widely dispersed across all strata," he added.
There are studies that find new risk factors for ASD almost on a daily basis, said Idan Menashe, assistant professor in the Department of Health at Ben-Gurion University of the Negev, the fastest growing research university in Israel.
"There are plenty of studies that find new genetic variants (and new genes)," he said. In addition, various prenatal and perinatal risk factors are associated with a risk of ASD. He cited a study his university conducted last year on the relationship between C-section births and ASD, which found that exposure to general anesthesia may explain the association.
Whatever the cause, health practitioners are seeing the consequences in real time.
"People say rates are higher because of the changes in the diagnostic criteria," said Dr. Roseann Capanna-Hodge, a psychologist in Ridgefield, CT. "And they say it's easier for children to get identified. I say that's not the truth and that I've been doing this for 30 years, and that even 10 years ago, I did not see the level of autism that I do see today."
Sure, we're better at detecting autism, she added, but the detection improvements have largely occurred at the low- to mid- level part of the spectrum. The higher rates of autism are occurring at the more severe end, in her experience.
A Polarizing Theory
Among the more controversial risk factors scientists are exploring is the role environmental toxins may play in the development of autism. Some scientists, doctors and mental health experts suspect that toxins like heavy metals, pesticides, chemicals, or pollution may interrupt the way genes are expressed or the way endocrine systems function, manifesting in symptoms of autism. But others firmly resist such claims, at least until more evidence comes forth. To date, studies have been mixed and many have been more associative than causative.
"Today, scientists are still trying to figure out whether there are other environmental changes that can explain this rise, but studies of this question didn't provide any conclusive answer," said Menashe, who also serves as the scientific director of the National Autism Research Center at BGU.
"It's not everything that makes Charlie. He's just like any other kid."
That inconclusiveness has not dissuaded some doctors from taking the perspective that toxins do play a role. "Autism rates are rising because there is a mismatch between our genes and our environment," said Julia Getzelman, a pediatrician in San Francisco. "The majority of our evolution didn't include the kinds of toxic hits we are experiencing. The planet has changed drastically in just the last 75 years –- it has become more and more polluted with tens of thousands of unregulated chemicals being used by industry that are having effects on our most vulnerable."
She cites BPA, an industrial chemical that has been used since the 1960s to make certain plastics and resins. A large body of research, she says, has shown its impact on human health and the endocrine system. BPA binds to our own hormone receptors, so it may negatively impact the thyroid and brain. A study in 2015 was the first to identify a link between BPA and some children with autism, but the relationship was associative, not causative. Meanwhile, the Food and Drug Administration maintains that BPA is safe at the current levels occurring in food, based on its ongoing review of the available scientific evidence.
Michael Mooney, President of St. Louis-based Delta Genesis, a non-profit organization that treats children struggling with neurodevelopmental delays like autism, suspects a strong role for epigenetics, which refers to changes in how genes are expressed as a result of environmental influences, lifestyle behaviors, age, or disease states.
He believes some children are genetically predisposed to the disorder, and some unknown influence or combination of influences pushes them over the edge, triggering epigenetic changes that result in symptoms of autism.
For Stefania Sterling, it doesn't really matter how or why she had an autistic child. That's only one part of Charlie.
"It's not everything that makes Charlie," she said. "He's just like any other kid. He comes with happy moments. He comes with sad moments. Just like my other three kids."
Can Genetic Testing Help Shed Light on the Autism Epidemic?
Autism cases are still on the rise, and scientists don't know why. In April, the Centers for Disease Control (CDC) reported that rates of autism had increased once again, now at an estimated 1 in 59 children up from 1 in 68 just two years ago. Rates have been climbing steadily since 2007 when the CDC initially estimated that 1 in 150 children were on the autism spectrum.
Some clinicians are concerned that the creeping expansion of autism is causing the diagnosis to lose its meaning.
The standard explanation for this increase has been the expansion of the definition of autism to include milder forms like Asperger's, as well as a heightened awareness of the condition that has improved screening efforts. For example, the most recent jump is attributed to children in minority communities being diagnosed who might have previously gone under the radar. In addition, more federally funded resources are available to children with autism than other types of developmental disorders, which may prompt families or physicians to push harder for a diagnosis.
Some clinicians are concerned that the creeping expansion of autism is causing the diagnosis to lose its meaning. William Graf, a pediatric neurologist at Connecticut Children's Medical Center, says that when a nurse tells him that a new patient has a history of autism, the term is no longer a useful description. "Even though I know this topic extremely well, I cannot picture the child anymore," he says. "Use the words mild, moderate, or severe. Just give me a couple more clues, because when you say autism today, I have no idea what people are talking about anymore."
Genetic testing has emerged as one potential way to remedy the overly broad label by narrowing down a heterogeneous diagnosis to a specific genetic disorder. According to Suma Shankar, a medical geneticist at the University of California, Davis, up to 60 percent of autism cases could be attributed to underlying genetic causes. Common examples include Fragile X Syndrome or Rett Syndrome—neurodevelopmental disorders that are caused by mutations in individual genes and are behaviorally classified as autism.
With more than 500 different mutations associated with autism, very few additional diagnoses provide meaningful information.
Having a genetic diagnosis in addition to an autism diagnosis can help families in several ways, says Shankar. Knowing the genetic origin can alert families to other potential health problems that are linked to the mutation, such as heart defects or problems with the immune system. It may also help clinicians provide more targeted behavioral therapies and could one day lead to the development of drug treatments for underlying neurochemical abnormalities. "It will pave the way to begin to tease out treatments," Shankar says.
When a doctor diagnoses a child as having a specific genetic condition, the label of autism is still kept because it is more well-known and gives the child access to more state-funded resources. Children can thus be diagnosed with multiple conditions: autism spectrum disorder and their specific gene mutation. However, with more than 500 different mutations associated with autism, very few additional diagnoses provide meaningful information. What's more, the presence or absence of a mutation doesn't necessarily indicate whether the child is on the mild or severe end of the autism spectrum.
Because of this, Graf doubts that genetic classifications are really that useful. He tells the story of a boy with epilepsy and severe intellectual disabilities who was diagnosed with autism as a young child. Years later, Graf ordered genetic testing for the boy and discovered that he had a mutation in the gene SYNGAP1. However, this knowledge didn't change the boy's autism status. "That diagnosis [SYNGAP1] turns out to be very specific for him, but it will never be a household name. Biologically it's good to know, and now it's all over his chart. But on a societal level he still needs this catch-all label [of autism]," Graf says.
"It gives some information, but to what degree does that change treatment or prognosis?"
Jennifer Singh, a sociologist at Georgia Tech who wrote the book Multiple Autisms: Spectrums of Advocacy and Genomic Science, agrees. "I don't know that the knowledge gained from just having a gene that's linked to autism," is that beneficial, she says. "It gives some information, but to what degree does that change treatment or prognosis? Because at the end of the day you have to address the issues that are at hand, whatever they might be."
As more children are diagnosed with autism, knowledge of the underlying genetic mutation causing the condition could help families better understand the diagnosis and anticipate their child's developmental trajectory. However, for the vast majority, an additional label provides little clarity or consolation.
Instead of spending money on genetic screens, Singh thinks the resources would be better used on additional services for people who don't have access to behavioral, speech, or occupational therapy. "Things that are really going to matter for this child in their future," she says.
This past March, headlines suddenly flooded the Internet about a startup company called Nectome. Founded by two graduates of the Massachusetts Institute of Technology, the new company was charging people $10,000 to join a waiting list to have their brains embalmed, down to the last neuron, using an award-winning chemical compound.
While the lay public presumably burnt their wills and grew ever more excited about the end of humanity's quest for immortality, neurologists let out a collective sigh.
Essentially, participants' brains would turn to a substance like glass and remain in a state of near-perfect preservation indefinitely. "If memories can truly be preserved by a sufficiently good brain banking technique," Nectome's website explains, "we believe that within the century it could become feasible to digitize your preserved brain and use that information to recreate your mind." But as with most Faustian bargains, Nectome's proposition came with a serious caveat -- death.
That's right, in order for Nectome's process to properly preserve your connectome, the comprehensive map of the brain's neural connections, you must be alive (and under anesthesia) while the fluid is injected. This way, the company postulates, when the science advances enough to read and extract your memories someday, your vitrified brain will still contain your perfectly preserved essence--which can then be digitally recreated as a computer simulation.
Almost immediately this story gained buzz with punchy headlines: "Startup wants to upload your brain to the cloud, but has to kill you to do it," "San Junipero is real: Nectome wants to upload your brain," and "New tech firm promises eternal life, but you have to die."
While the lay public presumably burnt their wills and grew ever more excited about the end of humanity's quest for immortality, neurologists let out a collective sigh -- hype had struck the scientific community once again.
The truth about Nectome is that its claims are highly speculative and no hard science exists to suggest that our connectome is the key to our 'being,' nor that it can ever be digitally revived. "We haven't come even close to understanding even the most basic types of functioning in the brain," says neuroscientist Alex Fox, who was educated at the University of Queensland in Australia. "Memory storage in the brain is only a theoretical concept [and] there are some seriously huge gaps in our knowledge base that stand in the way of testing [the connectome] theory."
After the Nectome story broke, Harvard computational neuroscientist Sam Gershman tweeted out:
"Didn't anyone tell them that we've known the C Elegans (a microscopic worm) connectome for over a decade but haven't figured out how to reconstruct all of their memories? And that's only 7000 synapses compared to the trillions of synapses in the human brain!"
Hype can come from researchers themselves, who are under an enormous amount of pressure to publish original work and maintain funding.
How media coverage of Nectome went from an initial fastidiously researched article in the MIT Technology Review by veteran science journalist Antonio Regalado to the click-bait frenzy it became is a prime example of the 'science hype' phenomenon. According to Adam Auch, who holds a doctorate in philosophy from Dalhousie University in Nova Scotia, Canada, "Hype is a feature of all stages of the scientific dissemination process, from the initial circulation of preliminary findings within particular communities of scientists, to the process by which such findings come to be published in peer-reviewed journals, to the subsequent uptake these findings receive from the non-specialist press and the general public."
In the case of Nectome, hype was present from the word go. Riding the high of several major wins, including having raised over one million dollars in funding and partnering with well-known MIT neurologist Edward Boyden, Nectome founders Michael McCanna and Robert McIntyre launched their website on March 1, 2018. Just one month prior, they were able to purchase and preserve a newly deceased corpse in Portland, Oregon, showing that vitrifixation, their method of chemical preservation, could be used on a human specimen. It had previously won an award for preserving every synaptic structure on a rabbit brain.
The Nectome mission statement, found on its website, is laced with saccharine language that skirts the unproven nature of the procedure the company is peddling for big bucks: "Our mission is to preserve your brain well enough to keep all its memories intact: from that great chapter of your favorite book to the feeling of cold winter air, baking an apple pie, or having dinner with your friends and family."
This rhetoric is an example of hype that can come from researchers themselves, who are under an enormous amount of pressure to publish original work and maintain funding. As a result, there is a constant push to present science as "groundbreaking" when really, as is apparently the case with Nectome, it is only a small piece in a much larger effort.
Calling out the audacity of Nectome's posited future, neuroscientist Gershman commented to another publication, "The important question is whether the connectome is sufficient for memory: Can I reconstruct all memories knowing only the connections between neurons? The answer is almost certainly no, given our knowledge about how memories are stored (itself a controversial topic)."
The former home page of Nectome's website, which has now been replaced by a statement titled, "Response to recent press."
Furthermore, universities like MIT, who entered into a subcontract with Nectome, are under pressure to seek funding through partnerships with industry as a result of the Bayh-Dole Act of 1980. Also known as the Patent and Trademark Law Amendments Act, this piece of legislation allows universities to commercialize inventions developed under federally funded research programs, like Nectome's method of preserving brains, formally called Aldehyde-Stabilized Cryopreservation.
"[Universities use] every incentive now to talk about innovation," explains Dr. Ivan Oransky, president of the Association of Health Care Journalists and co-founder of retractionwatch.com, a blog that catalogues errors and fraud in published research. "Innovation to me is often a fancy word for hype. The role of journalists should not be to glorify what universities [say, but to] tell the closest version of the truth they can."
In this case, a combination of the hyperbolic press, combined with some impressively researched expose pieces, led MIT to cut its ties with Nectome on April 2nd, 2018, just two weeks after the news of their company broke.
The solution to the dangers of hype, experts say, is a more scientifically literate public—and less clickbait-driven journalism.
Because of its multi-layered nature, science hype carries several disturbing consequences. For one, exaggerated coverage of a discovery could mislead the public by giving them false hope or unfounded worry. And media hype can contribute to a general mistrust of science. In these instances, people might, as Auch puts it, "fall back on previously held beliefs, evocative narratives, or comforting biases instead of well-justified scientific evidence."
All of this is especially dangerous in today's 'fake news' era, when companies or political parties sow public confusion for their own benefit, such as with global warming. In the case of Nectome, the danger is that people might opt to end their lives based off a lacking scientific theory. In fact, the company is hoping to enlist terminal patients in California, where doctor-assisted suicide is legal. And 25 people have paid the $10,000 to join Nectome's waiting list, including Sam Altman, president of the famed startup accelerator Y Combinator. Nectome now has offered to refund the money.
Founders McCanna and McIntyre did not return repeated requests for comment for this article. A new statement on their website begins: "Vitrifixation today is a powerful research tool, but needs more research and development before anyone considers applying it in a context other than research."
The solution to the dangers of hype, experts say, is a more scientifically literate public—and less clickbait-driven journalism. Until then, it seems that companies like Nectome will continue to enjoy at least 15 minutes of fame.