Why Are Autism Rates Steadily Rising?
Stefania Sterling with her son Charlie, who was diagnosed at age 3 with autism.
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."
Today’s more than 20,000 mental health apps have a wide range of functionalities and business models. Many of them can be useful for depression.
Even before the pandemic created a need for more telehealth options, depression was a hot area of research for app developers. Given the high prevalence of depression and its connection to suicidality — especially among today’s teenagers and young adults who grew up with mobile devices, use them often, and experience these conditions with alarming frequency — apps for depression could be not only useful but lifesaving.
“For people who are not depressed, but have been depressed in the past, the apps can be helpful for maintaining positive thinking and behaviors,” said Andrea K. Wittenborn, PhD, director of the Couple and Family Therapy Doctoral Program and a professor in human development and family studies at Michigan State University. “For people who are mildly to severely depressed, apps can be a useful complement to working with a mental health professional.”
Health and fitness apps, in general, number in the hundreds of thousands. These are driving a market expected to reach $102.45 billion by next year. The mobile mental health app market is a small part of this but still sizable at $500 million, with revenues generated through user health insurance, employers, and direct payments from individuals.
Apps can provide data that health professionals cannot gather on their own. People’s constant interaction with smartphones and wearable devices yields data on many health conditions for millions of patients in their natural environments and while they go about their usual activities. Compared with the in-office measurements of weight and blood pressure and the brevity of doctor-patient interactions, the thousands of data points gathered unobtrusively over an extended time period provide a far better and more detailed picture of the person and their health.
At their most advanced level, apps for mental health, including depression, passively gather data on how the user touches and interacts with the mobile device through changes in digital biomarkers that relate to depressive symptoms and other conditions.
Building on three decades of research since early “apps” were used for delivering treatment manuals to health professionals, today’s more than 20,000 mental health apps have a wide range of functionalities and business models. Many of these apps can be useful for depression.
Some apps primarily provide a virtual connection to a group of mental health professionals employed or contracted by the app. Others have options for meditation, sleeping or, in the case of industry leaders Calm and Headspace, overall well-being. On the cutting edge are apps that detect changes in a person’s use of mobile devices and their interactions with them.
Apps such as AbleTo, Happify Health, and Woebot Health focus on cognitive behavioral therapy, a type of counseling with proven potential to change a person’s behaviors and feelings. “CBT has been demonstrated in innumerable studies over the last several decades to be effective in the treatment of behavioral health conditions such as depression and anxiety disorders,” said Dr. Reena Pande, chief medical officer at AbleTo. “CBT is intended to be delivered as a structured intervention incorporating key elements, including behavioral activation and adaptive thinking strategies.”
These CBT skills help break the negative self-talk (rumination) common in patients with depression. They are taught and reinforced by some self-guided apps, using either artificial intelligence or programmed interactions with users. Apps can address loneliness and isolation through connections with others, even when a symptomatic person doesn’t feel like leaving the house.
At their most advanced level, apps for mental health, including depression, passively gather data on how the user touches and interacts with the mobile device through changes in “digital biomarkers” that can be associated with onset or worsening of depressive symptoms and other cognitive conditions. In one study, Mindstrong Health gathered a year’s worth of data on how people use their smartphones, such as scrolling through articles, typing and clicking. Mindstrong, whose founders include former leaders of the National Institutes of Health, modeled the timing and order of these actions to make assessments that correlated closely with gold-standard tests of cognitive function.
National organizations of mental health professionals have been following the expanding number of available apps over the years with keen interest. App Advisor is an initiative of the American Psychiatric Association that helps psychiatrists and other mental health professionals navigate the issues raised by mobile health technology. App Advisor does not rate or recommend particular apps but rather provides guidance about why apps should be assessed and how health professionals can do this.
A website that does review mental health apps is One Mind Psyber Guide, an independent nonprofit that partners with several national organizations. One Mind users can select among numerous search terms for the condition and therapeutic approach of interest. Apps are rated on a five-point scale, with reviews written by professionals in the field.
Do mental health apps related to depression have the kind of safety and effectiveness data required for medications and other medical interventions? Not always — and not often. Yet the overall results have shown early promise, Wittenborn noted.
“Studies that have attempted to detect depression from smartphone and wearable sensors [during a single session] have ranged in accuracy from about 86 to 89 percent,” Wittenborn said. “Studies that tried to predict changes in depression over time have been less accurate, with accuracy ranging from 59 to 85 percent.”
The Food and Drug Administration encourages the development of apps and has approved a few of them—mostly ones used by health professionals—but it is generally “hands off,” according to the American Psychiatric Association. The FDA has published a list of examples of software (including programming of apps) that it does not plan to regulate because they pose low risk to the public. First on the list is software that helps patients with diagnosed psychiatric conditions, including depression, maintain their behavioral coping skills by providing a “Skill of the Day” technique or message.
On its App Advisor site, the American Psychiatric Association says mental health apps can be dangerous or cause harm in multiple ways, such as by providing false information, overstating the app’s therapeutic value, selling personal data without clearly notifying users, and collecting data that isn’t relevant to mental health.
Although there is currently reason for caution, patients may eventually come to expect mental health professionals to recommend apps, especially as their rating systems, features and capabilities expand. Through such apps, patients might experience more and higher quality interactions with their mental health professionals. “Apps will continue to be refined and become more effective through future research,” said Wittenborn. “They will become more integrated into practice over time.”
Podcast: Has the First 150-Year-Old Already Been Born
In today's podcast episode, Steven Austad explains why we should want to live a long time as long as that involves longer healthspans.
Steven Austad is a pioneer in the field of aging, with over 200 scientific papers and book chapters on pretty much every aspect of biological aging that you could think of. He’s also a strong believer in the potential for anti-aging therapies, and he puts his money where his mouth is. In 2001, he bet a billion dollars that the first person to reach 150-years-old had already been born. I had a chance to talk with Steven for today’s podcast and asked if he still thinks the bet was a good idea, since the oldest person so far (that we know of), Jeanne Calment, died back in 1997. A few days after our conversation, the oldest person in the world, Kane Tanaka, died at 119.
Steven is the Protective Life Endowed Chair in Health Aging Research, a Distinguished Professor and Chair of the Department of Biology at the University of Alabama Birmingham. He's also Senior Scientific Director of the American Federation for Aging Research, which is managing a groundbreaking longevity research trial that started this year. Steven is also a great science communicator with five books, including one that comes out later this year, Methuselah’s Zoo, and he publishes prolifically in national media outlets.
See the rest of his bio linked below in the show notes.
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Steven Austad is featured in the latest episode of Making Sense of Science. He's a distinguished professor of biology at the University of Alabama Birmingham and has a new book due to be published in August, Methuselah's Zoo.
Photo by Steve Wood
Show notes:
2:36 - Steven explains why a particular opossum convinced him to dedicate his career to studying longevity.
6:48 - Steven's billion dollar bet that someone alive today will make it to 150-years-old.
9:15 - The most likely people to make it to 150 (Hint: not men).
10:38 - I ask Steven about Elon Musk’s comments this month that if people lived a really long time, “we’d be stuck with old ideas and society wouldn’t advance.” Steve isn’t so fond of that take.
13:34 - Why women are winning maybe the most important battle of sexes: staying alive. This is an area that Steven has led research on (see show notes).
18:20 - Why women, on average, actually have more morbidities earlier than men, even though they live longer.
23:10 - How the pandemic could affect sex differences in longevity.
24:55 - How often should people work out and get other physical activity to maximize longevity and health span?
29:09 - Steven gave me the latest update on the TAME trial on metformin, and how he and others longevity experts designed this groundbreaking research on longevity not in their offices, not on a zoom call, but in a castle in the Spanish countryside.
32:10 - Which anti-aging therapies are the most promising at this point for future research.
39:32 - The drug cocktail approach to address multiple hallmarks of aging.
41:00 - How to read health news like a scientist.
45:38 - Should we try a Manhattan project for aging?
48:47 - Can Jeff Bezos and Larry Ellison help us live to 150?
Show links:
Steven Austad's bio
Pre-order Steven's new book, Methuselah's Zoo - https://www.amazon.com/dp/B09M2QGRJR/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
Steven's journal article on Sex Differences in Lifespan - https://pubmed.ncbi.nlm.nih.gov/27304504/
Elon Musk's comments on super longevity "asphyxiating" society - https://www.cnbc.com/2022/04/11/elon-musk-on-avoid...
Steven's article on how to read news articles about health like a pro - https://www.nextavenue.org/how-to-read-health-news...
AFAR's research on Targeting Aging with Metformin (TAME) - https://www.afar.org/tame-trial