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.
The Latest News
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."
A female doctor giving encouragement to an elderly patient.
Taboo topics occupy a difficult place in the history of medicine. Society has long been reticent about confronting stigmatized conditions, forcing many patients to suffer in silence and isolation, often with poorer care.
"Classically, doctors don't purposely kill people. That is really the core of the resistance."
AIDS activists recognized this in the 1980s when they coined the phrase Silence = Death to generate public debate and action over a growing epidemic that until then had existed largely in the shadows. The slogan and the activists behind it were remarkably successful at changing the public discourse.
It is not a lone example. Post-World War II medicine is better because it came to deal more forthrightly with a broad range of medical conditions from conception/abortion, to cancer, to sexually transmitted infections. The most recent issue to face such scrutiny is physician-assisted dying (PAD).
"Classically, doctors don't purposely kill people…that is really the core of the resistance" to PAD from the provider perspective, says Neil Wenger, an internist and ethicist at the University of California Los Angeles who focuses on end-of-life issues.
But from the patient perspective, the option of PAD "provides important psychological benefits ... because it gives the terminally ill autonomy, control, and choice," argued the American Public Health Association in support of Oregon's death with dignity legislation.
Jack Kervorkian, "Dr. Death," was one of the first to broach the subject when few in polite society were willing to do so. The modern era truly began twenty years ago when the citizens of Oregon embraced the option of death with dignity in a public referendum, over the objections of their political leaders.
Expansion of the legal option in North America was incremental until 2016 when the Supreme Court in Canada and legislators in California decided that control over one's body extended to death, at least under certain explicit conditions.
An estimated 18 percent of Americans now live in jurisdictions that provide the legal option of assisted death, but exercising that right can be difficult. Only a fraction of one percent of deaths are by PAD, even in Oregon.
Stakeholder Roles
Few organizations of healthcare professionals in the U.S. support PAD; some actively oppose it, others have switched to a position of neutrality while they study the issue.
One doctor wanted to organize a discussion of physician-assisted dying at his hospital, but administrators forbade it.
But once a jurisdiction makes the political/legal decision that patients have a right to physician-assisted death, what are the roles and responsibilities of medical stakeholders? Can they simply opt out in a vow of silence? Or do organizations bear some sort of obligation to ensure access to that right, no matter their own position, particularly when they are both regulated by and receive operating funds from public sources?
The law in California and other U.S. jurisdictions reflects ambivalence about PAD by treating it differently from other medical practices, says David Magnus, an ethicist at Stanford University School of Medicine. It is allowed but "it's intentionally a very, very burdensome process."
Medical decisions, including withdrawing life support or a do not resuscitate [DNR] order, are between a physician and the patient or guardian. But PAD requires outside consultation and documentation that is quite rigorous, even burdensome, Magnus explains. He recalls one phone consult with a physician who had to re-have a conversation with a patient at home in order to meet the regulatory requirements for a request for assistance in dying. "So it is not surprising that it is utilized so infrequently."
The federal government has erected its own series of barriers. Roused by the experience in Oregon, opponents tried to ban PAD at the national level. They failed but did the next best thing; they prohibited use of federal funds to pay for or even discuss PAD. That includes Medicare, Medicaid, and the large health delivery systems run by the Pentagon and Veterans Affairs. The restrictions parallel those on federal funding for access to abortion and medical marijuana.
Even physicians who support and perform PAD are reluctant to talk about it. They are unwilling to initiate the discussion with patients, says Mara Buchbinder, a bioethicist at the University of North Carolina at Chapel Hill who has interviewed physicians, patients, and families about their experience with assisted dying in Vermont.
"There is a stigma for health care workers to talk about this; they feel that they are not supported," says Buchbinder. She relates how one doctor wanted to organize a discussion of PAD at his hospital, but administrators forbade it. And when the drug used to carry out the procedure became prohibitively expensive, other physicians were not aware of alternatives.
"This just points to large inadequacies in medical preparation around end-of-life conversations," says Buchbinder, a view endorsed by many experts interviewed for this article.
These inadequacies are reinforced when groups like the Coalition to Transform Advanced Care (C-TAC), a 140-member organizational alliance that champions improved end-of-life care, dodges the issue. A spokesman said simply, PAD "is not within the scope of our work."
The American Medical Association has had a policy in place opposing PAD since 1993. Two years ago, its House of Delegates voted to reevaluate their position in light of evolving circumstances. Earlier this year the Council of Ethical and Judicial Affairs recommended continued opposition, but in June, the House of Delegates rejected that recommendation (56 to 44 percent) and directed the Council to keep studying the issue.
Only those with the economic and social capital and network of advocates will succeed in exercising this option.
Kaiser Permanente has provided assisted dying to its members in multiple states beginning with Oregon and has done "a wonderful job" according to supporters of PAD. But it has declined to discuss those activities publicly despite a strenuous effort to get them to do so.
Rather than drawing upon formal structures for leadership and guidance, doctors who are interested in learning more about PAD are turning to the ad hoc wisdom of providers from Oregon and Washington who have prior experience. Magnus compares it with what usually happens when a new intervention or technology comes down the pike: "People who have done it, have mastered it, pass that knowledge on to other people so they know how to do it."
Buchbinder says it becomes an issue of social justice when providers are not adequately trained, and when patients are not ordinarily offered the option of a medical service in jurisdictions where it is their right.
Legalization of PAD "does not guarantee practical access, and well-intentioned policies designed to protect vulnerable groups may at times reinforce or exacerbate health care inequalities," she says. Only those with the economic and social capital and network of advocates will succeed in exercising this option.
O Canada
Canada provides a case study of how one might address PAD. They largely settled on the term medical aid in dying – often shortened to MAID – as the more neutral phrase for their law and civil discourse.
The Canadian Medical Association (CMA) decided early on to thread the needle; to not take a position on the core issue of morality but to proactively foster public discussion of those issues as the legal challenge to the ban on assisted dying headed to that country's Supreme Court.
"We just felt that it was too important for the profession to sit on the sidelines and not be part of the discussion," says Jeff Blackmer, CMA's vice president for medical professionalism.
It began by shifting the focus of discussion from a yes/no on the morality of MAID to the questions of, "If the court rules that the current laws are unconstitutional, and they allow assisted dying, how should the profession react and how should we respond? And how does the public think that the profession should respond?"
"I had to wear a flack jacket, a bulletproof vest, and there were plainclothes police officers with guns in the audience because it is really really very controversial."
The CMA teamed up with Maclean's magazine to host a series of five town hall meetings throughout the country. Assisted dying was discussed in a context of palliative care, advanced care planning, and other end-of-life issues.
There was fear that MAID might raise passions and even violence that has been seen in recent controversies over abortion. "I had to wear a flack jacket, a bulletproof vest, and there were plainclothes police officers with guns in the audience because it is really really very controversial," Blackmer recalls. Thankfully there were no major incidents.
The CMA also passed a resolution at its annual meeting supporting the right of its members to opt out of participating in MAID, within the confines of whatever law might emerge.
Once legislation and regulations began taking shape, the CMA created training materials on the ethical, legal, and practical consideration that doctors and patients might face. It ordinarily does not get involved with clinical education and training.
Stefanie Green is president of Canadian Association of MAID Assessors & Providers, a professional medical association that supports those working in the area of assisted dying, educates the public and health care community, and provides leadership on setting medical standards. Green acknowledges the internal pressures the CMA faced, and says, "I do understand their stance is as positive as it gets for medical associations."
Back in the USofA
Prohibitionism – the just say no approach – does not work when a substantial number of people want something, as demonstrated with alcohol, marijuana, opioids for pain relief, and reproductive control. Reason suggests a harm reduction strategy is the more viable approach.
"Right now we're stuck in the worst of all worlds because we've made [PAD] sort of part of medicine, but sort of illicit and sort of shameful. And we sort of allow it, but we sort of don't, we make it hard," says Stanford's Magnus. "And that's a no man's land where we are stuck."
A rendering of DNA with a judge's gavel.
Imagine this scenario: A couple is involved in a heated custody dispute over their only child. As part of the effort to make the case of being a better guardian, one parent goes on a "genetic fishing expedition": this parent obtains a DNA sample from the other parent with the hope that such data will identify some genetic predisposition to a psychiatric condition (e.g., schizophrenia) and tilt the judge's custody decision in his or her favor.
As knowledge of psychiatric genetics is growing, it is likely to be introduced in civil cases, such as child custody disputes and education-related cases, raising a tangle of ethical and legal questions.
This is an example of how "behavioral genetic evidence" -- an umbrella term for information gathered from family history and genetic testing about pathological behaviors, including psychiatric conditions—may in the future be brought by litigants in court proceedings. Such evidence has been discussed primarily when criminal defendants sought to introduce it to make the claim that they are not responsible for their behavior or to justify their request for reduced sentencing and more lenient punishment.
However, civil cases are an emerging frontier for behavioral genetic evidence. It has already been introduced in tort litigation, such as personal injury claims, and as knowledge of psychiatric genetics is growing, it is further likely to be introduced in other civil cases, such as child custody disputes and education-related cases. But the introduction of such evidence raises a tangle of ethical and legal questions that civil courts will need to address. For example: how should such data be obtained? Who should get to present it and under what circumstances? And does the use of such evidence fit with the purposes of administering justice?
How Did We Get Here?
That behavioral genetic evidence is entering courts is unsurprising. Scientific evidence is a common feature of judicial proceedings, and genetic information may reveal relevant findings. For example, genetic evidence may elucidate whether a child's medical condition is due to genetic causes or medical malpractice, and it has been routinely used to identify alleged offenders or putative fathers. But behavioral genetic evidence is different from such other genetic data – it is shades of gray, instead of black and white.
Although efforts to understand the nature and origins of human behavior are ongoing, existing and likely future knowledge about behavioral genetics is limited. Behavioral disorders are highly complex and diverse. They commonly involve not one but multiple genes, each with a relatively small effect. They are impacted by many, yet unknown, interactions between genes, familial, and environmental factors such as poverty and childhood adversity.
And a specific gene variant may be associated with more than one behavioral disorder and be manifested with significantly different symptoms. Thus, biomarkers about "predispositions" for behavioral disorders cannot generally provide a diagnosis or an accurate estimate of whether, when, and at what severity a behavioral disorder will occur. And, unlike genetic testing that can confirm litigants' identity with 99.99% probability, behavioral genetic evidence is far more speculative.
Genetic theft raises questions about whose behavioral data are being obtained, by whom, and with what authority.
Whether judges, jurors, and other experts understand the nuances of behavioral genetics is unclear. Many people over-estimate the deterministic nature of genetics, and under-estimate the role of environments, especially with regards to mental health status. The U.S. individualistic culture of self-reliance and independence may further tilt the judicial scales because litigants in civil courts may be unjustly blamed for their "bad genes" while structural and societal determinants that lead to poor behavioral outcomes are ignored.
These concerns were recently captured in the Netflix series "13 Reasons Why," depicting a negligence lawsuit against a school brought by parents of a high-school student there (Hannah) who committed suicide. The legal tides shifted from the school's negligence in tolerating a culture of bullying to parental responsibility once cross-examination of Hannah's mother revealed a family history of anxiety, and the possibility that Hannah had a predisposition for mental illness, which (arguably) required therapy even in the absence of clear symptoms.
Where Is This Going?
The concerns are exacerbated given the ways in which behavioral genetic evidence may come to court in the future. One way is through "genetic theft," where genetic evidence is obtained from deserted property, such as soft-drink cans. This method is often used for identification purposes such as criminal and paternity proceedings, and it will likely expand to behavioral genetic data once available through "home kits" that are offered by direct-to-consumer companies.
Genetic theft raises questions about whose behavioral data are being obtained, by whom, and with what authority. In the scenario of child-custody dispute, for example, the sequencing of the other parent's DNA will necessarily intrude on the privacy of that parent, even as the scientific value of such information is limited. A parent on a "genetic fishing expedition" can also secretly sequence their child for psychiatric genetic predispositions, arguably, in order to take preventative measures to reduce the child's risk for developing a behavioral disorder. But should a parent be allowed to sequence the child without the other parent's consent, or regardless of whether the results will provide medical benefits to the child?
Similarly, although schools are required, and may be held accountable for failing to identify children with behavioral disabilities and to evaluate their educational needs, some parents may decline their child's evaluation by mental health professionals. Should schools secretly obtain a sample and sequence children for behavioral disorders, regardless of parental consent? My study of parents found that the overwhelming majority opposed imposed genetic testing by school authorities. But should parental preference or the child's best interests be the determinative factor? Alternatively, could schools use secretly obtained genetic data as a defense that they are fulfilling the child-find requirement under the law?
The stigma associated with behavioral disorders may intimidate some people enough that they back down from just claims.
In general, samples obtained through genetic theft may not meet the legal requirements for admissible evidence, and as these examples suggest, they also involve privacy infringement that may be unjustified in civil litigation. But their introduction in courts may influence judicial proceedings. It is hard to disregard such evidence even if decision-makers are told to ignore it.
The costs associated with genetic testing may further intensify power differences among litigants. Because not everyone can pay for DNA sequencing, there is a risk that those with more resources will be "better off" in court proceedings. Simultaneously, the stigma associated with behavioral disorders may intimidate some people enough that they back down from just claims. For example, a good parent may give up a custody claim to avoid disclosure of his or her genetic predispositions for psychiatric conditions. Regulating this area of law is necessary to prevent misuses of scientific technologies and to ensure that powerful actors do not have an unfair advantage over weaker litigants.
Behavioral genetic evidence may also enter the courts through subpoena of data obtained in clinical, research or other commercial genomic settings such as ancestry testing (similar to the genealogy database recently used to identify the Golden State Killer). Although court orders to testify or present evidence are common, their use for obtaining behavioral genetic evidence raises concerns.
One worry is that it may be over-intrusive. Because behavioral genetics are heritable, such data may reveal information not only about the individual litigant but also about other family members who may subsequently be stigmatized as well. And, even if we assume that many people may be willing for their data in genomic databases to be used to identify relatives who committed crimes (e.g., a rapist or a murderer), we can't assume the same for civil litigation, where the public interest in disclosure is far weaker.
Another worry is that it may deter people from participating in activities that society has an interest in advancing, including medical treatment involving genetic testing and genomic research. To address this concern, existing policy provides expanded privacy protections for NIH-funded genomic research by automatically issuing a Certificate of Confidentiality that prohibits disclosure of identifiable information in any Federal, State, or local civil, criminal, and other legal proceedings.
But this policy has limitations. It applies only to specific research settings and does not cover non-NIH funded research or clinical testing. The Certificate's protections can also be waived under certain circumstances. People who volunteer to participate in non-NIH-funded genomic research for the public good may thus find themselves worse-off if embroiled in legal proceedings.
Consider the following: if a parent in a child custody dispute had participated in a genetic study on schizophrenia years earlier, should the genetic results be subpoenaed by the court – and weaponized by the other parent? Public policy should aim to reduce the risks for such individuals. The end of obtaining behavioral genetic evidence cannot, and should not, always justify the means.