By Giorgia Guglielmi Male and female human fetuses show distinct patterns of gene activity and DNA regulation in the cerebral cortex, according to a new analysis of thousands of individual brain cells. The study offers one of the most detailed maps to date of how such activity differs between boys and girls’ brains during the second trimester. It also compares sex differences in gene activity in fetuses with spontaneous genetic changes in autistic people, revealing clues as to how these de novo changes affect boys and girls. “As the field evolves, this [work] will be a helpful reference” for exploring sex-related molecular differences in early brain development, says Matthew Oetjens, assistant professor of human genetics at Geisinger Medical Center, who was not involved in the study. Understanding these differences may help explain why certain neurodevelopmental conditions are more common in one sex than the other, he says. Autism, for example, is diagnosed about four times more often in boys than in girls, but scientists are still trying to understand why. Theories include the possibility that boys are more vulnerable, girls are sometimes protected, or a combination of both. “We know that autism … has a very strong genetic component. What is not known is how the genetic risk architecture intersects with any differences at the molecular level that might exist between male and female human brains,” says study investigator Tomasz Nowakowski, associate professor of neurological surgery, anatomy and psychiatry, and behavioral sciences at the University of California, San Francisco. More than 940 genes are expressed differently between the sexes, according to the new analysis of more than 38,000 brain cells from 21 female and 27 male mid-gestation fetuses. Most of these differentially expressed genes are more active in females. © 2025 Simons Foundation

Related chapters from BN: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 13: Memory and Learning
Link ID: 29977 - Posted: 10.22.2025

By Azeen Ghorayshi As a child, Jodie Singer barely spoke. She could repeat words that people said to her or recite the book “Madeline” from beginning to end, but she could not answer yes or no when her mother asked if she wanted juice. Sometimes she hurt herself, compulsively tearing at the skin and hair on the nape of her neck. She threw tantrums, thrashing and refusing to be comforted. When she was almost 3, Jodie was given a diagnosis of autism. Now 28, she still speaks only in short, repetitive phrases and requires round-the-clock care, including help eating, getting dressed and using the toilet. At the time Jodie’s diagnosis was first made, the definition of autism was expanding, as it would continue to do over the next 25 years. Once primarily limited to severely disabled people, autism began to be viewed as a spectrum that included far less impaired children and adults. Along the way, it also became an identity, embraced by college graduates and even by some of the world’s most successful people, like Elon Musk and Bill Gates. That broadening of the diagnosis, autism experts believe, along with the increasing awareness of the disorder, is largely responsible for the steep rise in autism cases that Health Secretary Robert F. Kennedy Jr. has called “an epidemic” and has attributed to theories of causality that mainstream scientists reject, like vaccines and, more recently, Tylenol. And the diagnostic expansion has now become a flashpoint in a long-running debate over how autism should defined, one that has divided parents and activists, ignited social media battles and grown fiercer with Mr. Kennedy’s laser focus on autism. Speaking of autistic children in the spring, Mr. Kennedy said, “These are kids who will never pay taxes, they’ll never hold a job, they’ll never play baseball, they’ll never write a poem, they’ll never go out on a date.” His words drew a swift backlash from many autistic adults, who called his characterization of their lives false and dehumanizing. But Jodie’s mother, Alison Singer, said that, though she disagrees with Mr. Kennedy’s views on the causes of autism, his words about the harsh realities of living with the disorder spoke to families like her own. © 2025 The New York Times Company

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29947 - Posted: 10.01.2025

Jon Hamilton In a White House press conference Monday, President Trump and several deputies said the Food and Drug Administration would be updating drug labeling to discourage the use of acetaminophen by pregnant women, suggesting a link between the common painkiller and autism. Federal officials also said they would be changing the label for leucovorin, a form of vitamin B typically used in conjunction with cancer treatment, to enable its use as a treatment for autism. And they added that state Medicaid programs, in partnership with the federal Centers for Medicare & Medicaid Services, would cover this use. The suite of changes was announced despite a notable lack of clear scientific evidence to support these moves. The changes were presented as part of what the administration said was its commitment to identify the root causes of autism, diagnoses of which have increased in recent years. Flanked by Health and Human Services Secretary Robert F. Kennedy Jr. and Centers for Medicare and Medicaid head Dr. Mehmet Oz, President Trump pinned substantial blame for rising autism rates on the common painkiller, which is also known by its brand name, Tylenol. "Taking Tylenol is not good — I'll say it: It's not good," he said, suggesting without evidence that communities without access to the medicine have "no autism," while in others, autism now affects 1 in 12 boys. (An estimated 1 in 31 children in the U.S. are diagnosed with autism.) Trump discouraged giving acetaminophen to babies, as well. (He also suggested that vaccines and their frequency may be a culprit in causing autism, an oft-repeated claim that has been debunked by decades of research.) © 2025 npr

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29941 - Posted: 09.24.2025

By Christina Caron Dr. Marty Makary, the commissioner of the Food and Drug Administration, announced on Monday that the agency would be modifying the label of a relatively obscure medicine so that “it can be available for children with autism.” He was referring to leucovorin, or folinic acid, a modified version of vitamin B9, also known as folate — which is naturally found in beans, leafy greens, eggs, beets and citrus. Folate helps the body make red blood cells and is important for cell growth. It’s especially crucial during early pregnancy to lower the risk of major birth defects in a baby’s brain or spine. Studies suggest that folate levels can affect our health in various ways, and scientists are researching what role folate plays in depression, dementia, heart disease and autism. Some people have antibodies that interfere with how folate is transported within the body, and small studies suggest that a number of people with autism — in some cases up to 75 percent — may have these antibodies. In a Federal Register notice filed on Monday, the F.D.A. said it was approving leucovorin tablets for people with “cerebral folate deficiency,” based on a review of studies from 2009 to 2024 that found that they “improve certain symptoms.” The agency, noting that more studies were needed, cited one study that compared 40 people on the medication and 40 on a placebo; those who took the medication showed “substantial improvement” of the deficiency symptoms. The medicine has been used off-label to treat people diagnosed with cerebral folate deficiency for about two decades. Symptoms of cerebral folate deficiency usually begin to show up around the age of 2 when children start to experience speech difficulties, intellectual disabilities and, in some cases, seizures. They may also have tremors and difficulty controlling their muscle movements. © 2025 The New York Times Company

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29940 - Posted: 09.24.2025

Rachel Fieldhouse Last week, a study involving more than nine million pregnancies reported that children whose mothers had gestational diabetes during pregnancy had a higher chance of developing attention deficit–hyperactivity disorder (ADHD) and autism than did children whose mothers didn’t have the condition. The study, presented at the European Association for the Study of Diabetes in Vienna, is under review at a peer-reviewed journal. It is not the first to link gestational diabetes to neurodevelopmental disorders in children, but it is one of the largest. Researchers pooled results from 48 studies across 20 countries, finding that children born to people with gestational diabetes had lower IQ scores, a 36% higher risk of ADHD and a 56% higher risk of autism spectrum disorders. Estimates suggest the prevalence of autism in the general population is one in 127 people1 and between 3-10%2 of children and teenagers have ADHD. The latest results mirror those of another meta-analysis3 published in The Lancet Diabetes & Endocrinology journal in June, which included 56 million mother–child pairs and found that all types of diabetes in pregnancy, including type 1, type 2 and gestational diabetes, increase the risk of the baby developing ADHD and autism. But none of these studies have been able to show that diabetes during pregnancy causes these conditions. “There’s no doubt that there is a signal here, but certainly further research is required,” says Alex Polyakov, an obstetrician and researcher at the University of Melbourne in Australia. Long a topic of research, the causes of autism have been thrust into the spotlight by the administration of US President Donald Trump. On Sunday, while speaking at the memorial for conservative activist Charlie Kirk, Trump said: “I think we found an answer to autism. How about that?” © 2025 Springer Nature Limited

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29939 - Posted: 09.24.2025

Helen Pearson On 16 April, Robert F. Kennedy Jr held a press conference about rising diagnoses of autism. The US Health and Human Services (HHS) secretary pointed to new data showing that autism prevalence in the United States had risen steeply from one in 150 eight-year-olds in 2000 to one in 31 in 2022. He called it an “epidemic” caused by “an environmental toxin” — and said he would soon be announcing a study to find the responsible agent. The next month, the US National Institutes of Health (NIH), part of the department that Kennedy leads, announced the Autism Data Science Initiative (ADSI). The initiative offered up to US$50 million to fund studies on the causes of autism. The winning applications are expected to be announced in September. Usually, big investments in research are welcomed by scientists — but not this time. Many were dismayed that these developments seemed to ignore decades of work on the well-documented rise in autism diagnoses and on causes of the developmental condition. Although Kennedy said that environmental factors are the main cause of autism, research has shown that genetics plays a bigger part. Population studies1 have linked a handful of environmental factors — mostly encountered during pregnancy — to increased chances of autism, but their precise role has been hard to pin down. More than anything, research has shown that the drivers of autism are fiendishly complicated. “There will never be a sound-bite answer to what causes autism,” says Helen Tager-Flusberg, a psychologist who studies neurodevelopmental conditions at Boston University, Massachusetts. The rise in prevalence, many researchers say, is predominantly caused by an increase in diagnoses rather than a true rise in the underlying symptoms and traits. “We don’t see an epidemic of autism, but we see an ‘epidemic’ of diagnoses,” says Sven Bölte, a specialist in child and adolescent psychiatric science at the Karolinska Institute in Stockholm. Researchers are concerned that Kennedy, an anti-vaccine advocate, will use the ADSI to promote the disproven idea that vaccines are linked to autism. © 2025 Springer Nature Limited

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29905 - Posted: 08.27.2025

Welcome to Entanglements. In this episode, hosts Brooke Borel and Anna Rothschild ask: Should we try to prevent autism? It’s a question that has divided the autistic community, and the answer has significant implications on how to focus scientific research and funding. Their guests this week are Jill Escher, a philanthropist, president of the National Council on Severe Autism, and parent of two young adults with severe nonverbal autism, and Eric García, the Washington bureau chief at The Independent and the author of “We’re Not Broken: Changing the Autism Conversation,” who is himself autistic. Robert F. Kennedy Jr: These are kids who will never pay taxes, they’ll never hold a job, they’ll never play baseball, they’ll never write a poem, they’ll never go out on a date. Many of them will never use a toilet unassisted. And we have to recognize we are doing this to our children. Anna Rothschild: That was Health and Human Services Secretary Robert F. Kennedy Jr., talking about autism back in April of 2025. And he promised to find some answers about the cause of the condition, which he called an epidemic. Robert F. Kennedy Jr: This is a preventable disease. We know it’s an environmental exposure. It has to be. Genes do not cause epidemics. Anna Rothschild: On that note, welcome to Entanglements, the show where we wade into the murkiest scientific controversies and search for common ground. I’m science journalist Anna Rothschild. Brooke Borel: And I’m Brooke Borel, articles editor at Undark Magazine. And that was a dramatic cold open. Anna, what’s happening here? Are you about to do an episode on whether vaccines cause autism? Anna Rothschild: No, that is not a murky controversy. That has been rigorously disproven. Brooke Borel: Yeah. Anna Rothschild: No, today we are asking the question: Should we try to prevent autism?

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29904 - Posted: 08.27.2025

By Ellen Barry Thirty-six hours after dropping his date off at her apartment, Bradley Goldman was on a video call with his dating coach, breaking down the events of the evening. Listen to this article with reporter commentary For one thing, he told the coach, he had chosen the wrong venue for someone on the autism spectrum — a bar of the Sunset Strip hipster variety, so loud and overstimulating that he could almost feel himself beginning to dissociate. Mr. Goldman, a tall, rangy 42-year-old who works as an office manager, hadn’t decided in advance of the date whether to mention that he had been diagnosed with autism, or that he was working with a coach. So he deflected, and they found themselves, briefly, in a conversational blind alley. “I struggle with how to disclose,” he said. “Do I say I am ‘neuro-spicy’? Or ‘neurodiverse’? Or do I disclose at all?” His coach, Disa Jean-Pierre, was sympathetic. “You could just wait for it to come up naturally after a few dates,” she suggested. Mr. Goldman thought this over. “I’m still figuring this out,” he said. Nevertheless, it was a solidly enjoyable date, something he credited to the coaching he had received from a team of psychologists at the Semel Institute for Neuroscience and Human Behavior at the University of California, Los Angeles. He had avoided “info dumping” or making too many Jeffrey Dahmer jokes, and he had carefully observed his date’s body language to detect whether she was signaling openness to a good night kiss. (She was.) “She was like, ‘I really want you to let me know you got home,’” he said. “So, that © 2025 The New York Times Company

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29826 - Posted: 06.14.2025

By Lina Zeldovich When Catherine Lord was a psychology student a half century ago, she took part in a pioneering effort to move kids with autism from psychiatric institutions into the community. Lord was inspired by positive changes in the kids and devoted her life to developing therapies for people with autism and understanding the biology of the condition. Today, Lord is a professor of psychiatry at the University of California, Los Angeles, and renowned worldwide for developing tools to diagnose autism, which have become clinical standards, and for her efforts to improve the lives of people with autism and their families. Along with her research, Lord maintains a clinical practice where she works with people with autism, from toddlers to adults. So I couldn’t think of a better scientist to address the views of autism espoused by Robert F. Kennedy, Jr. Since being appointed as the United States Secretary of Health and Human Services, Kennedy has continued to spread misinformation about the condition, a pattern that began two decades ago when he claimed childhood vaccines cause autism, a charge long ago proven to be false. Earlier this year, Kennedy announced the National Institutes of Health would launch a new study to investigate the causes of autism. To conduct its study, he said, the NIH would gather medical records of Americans with autism from federal and commercial databases. In conversation, Lord spoke with authority and concern as she pointed out the mendacity and danger of Kennedy’s comments, and clarified the state of autism research and science. He has made a variety of statements about autism that suggests he doesn’t really know what he’s talking about. © 2025 NautilusNext Inc.,

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29818 - Posted: 06.04.2025

By Sara Talpos It’s been more than 30 years since the award-winning film “Rain Man,” starring Dustin Hoffman and Tom Cruise, put a spotlight on autism — or, more specifically, on a specific type of autism characterized by social awkwardness and isolation and typically affecting males. Yet as far back as the 1980s, at least one prominent autism researcher wondered whether autism’s male skew might simply reflect the fact that autistic females were, for some reason, going undiagnosed. Over the past decade, spurred by the personal testimonies of late-diagnosed women, autism researchers have increasingly examined this question. As it turns out, many autistic women and girls are driven by a powerful desire to avoid social rejection, so powerful, in fact, that they may adopt two broad strategies — camouflaging and masking — to hide their condition in an attempt to better fit in with neurotypical peers and family members. Such behavior is “at odds with the traditional picture of autism,” writes Gina Rippon, an emeritus professor of cognitive neuroimaging at Aston University in Birmingham, England, in her new book “Off the Spectrum: Why the Science of Autism Has Failed Women and Girls.” And while the ability to blend in might seem like a positive, it can ultimately take a heavy toll. Rippon points, for example, to surveys showing that by age 25, about 20 percent of autistic women have been hospitalized for a psychiatric condition, more than twice the rate of autistic men. In the U.S., the rate of autism has been increasing since at least 2000, and many autism researchers, including Rippon, believe more inclusive diagnostic criteria, coupled with increased awareness, have contributed to the rise. Last week, however, Health and Human Services Secretary Robert F. Kennedy Jr. dismissed this idea and insisted that the condition is caused by environmental factors. The National Institutes of Health has begun work on a research initiative that aims to look into this further.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 8: Hormones and Sex
Link ID: 29758 - Posted: 04.26.2025

By Azeen Ghorayshi The percentage of American children estimated to have autism spectrum disorder increased in 2022, continuing a long-running trend, according to data released on Tuesday by the Centers for Disease Control and Prevention. Among 8-year-olds, one in 31 were found to have autism in 2022, compared with 1 in 36 in 2020. That rate is nearly five times as high as the figure in 2000, when the agency first began collecting data. The health agency noted that the increase was most likely being driven by better awareness and screening, not necessarily because autism itself was becoming more common. That diverged sharply from the rhetoric of the nation’s health secretary, Robert F. Kennedy Jr., who on Tuesday said, “The autism epidemic is running rampant.” Mr. Kennedy has repeatedly tried to connect rising autism rates with vaccines, despite dozens of studies over decades that failed to establish such a link. The health secretary nonetheless has initiated a federal study that will revisit the possibility and has hired a well-known vaccine skeptic to oversee the effort. Mr. Kennedy recently announced an effort by the Department of Health and Human Services to pinpoint the “origins of the epidemic” by September, an initiative that was greeted with skepticism by many autism experts. “It seems very unlikely that it is an epidemic, in the way that people define epidemics,” said Catherine Lord, a psychologist and autism researcher at the David Geffen School of Medicine at the University of California, Los Angeles. A significant part of the increase instead can be attributed to the expansion of the diagnosis over the years to capture milder cases, Dr. Lord said, as well as decreased stigma and greater awareness of support services. Still, she left open the possibility that other factors are contributing to more children developing autism. “We can account for a lot of the increase but perhaps not all of it,” Dr. Lord said. “But whatever it is, it’s not vaccines,” she added. © 2025 The New York Times Company

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29744 - Posted: 04.16.2025

By Catherine Offord In scientists’ search to understand the causes of autism, a spotlight has fallen on maternal health during pregnancy. Based partly on association studies, researchers have proposed that conditions including obesity and depression during pregnancy could lead to autism in a child by affecting fetal neurodevelopment. But a study of more than 1 million Danish children and their families, published today in Nature Medicine, pushes back against this view. Researchers analyzed more than 200 health conditions that occurred in these children’s mothers before or during pregnancy. They conclude that many of the supposed links to a child’s autism diagnosis may not be causal, and instead reflect inherited genetic variants or environmental factors shared within families. “It’s a very comprehensive and well-done study,” says Håkan Karlsson, a neuroscientist at the Karolinska Institute who was not involved in the work. It suggests “conditions [pregnant people] suffered from during pregnancy are probably not the cause of autism in their kid.” The findings dovetail with a growing view in the field that shared genetics could explain a lot of the apparent connections between maternal health and autism, adds Drexel University epidemiologist Brian Lee. However, he and others caution the study doesn’t rule out that some conditions during pregnancy could have a causative role, nor does it identify factors that do influence the likelihood of autism. Previous research has linked conditions such as maternal obesity, psychiatric disorders, and pregnancy or birth complications to an increased likelihood of autism diagnoses in children. Such findings can lead some pregnant people to feel that “if they get this or that condition, their [child’s] chance of autism may increase,” says Magdalena Janecka, an epidemiologist at New York University’s Grossman School of Medicine and a co-author on the new paper. © 2025 American Association for the Advancement of Science.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29652 - Posted: 02.01.2025

By Holly Barker Previously unrecognized genetic changes on the X chromosome of autistic people could explain the higher prevalence of the condition among men and boys than among women and girls, according to two new studies. About 60 variants are more common in people with autism than in those without the condition, an analysis of roughly 15,000 X chromosomes revealed. Several of the variants are in Xp22.11, a region of the X chromosome linked to autism in boys and men. In the second study, the team pinpointed 27 autism-linked variants in DDX53, one of the genes in the vulnerable region that had not been tied to the condition in past research. Those findings could help explain why autism is diagnosed three to four times more often in boys than girls, according to the study investigators, led by Stephen Scherer, chief of research at SickKids Research Institute. Although that disparity is likely influenced by social factors—male-only studies could lead to autism being less recognizable in women and girls, and girls may be conditioned to mask their autism traits—there is also a clear biological component. The X chromosome plays an outsized role in brain development, and many genes on the chromosome are strongly linked to autism, previous studies have found. Still, the sex chromosomes have been mostly ignored in genetic searches of autism variants, says Aaron Besterman, associate clinical professor of psychiatry at the University of California, San Diego, who was not involved in the work. “It’s been a dirty little secret that for a long time the X chromosome has not been well interrogated from a genetics perspective,” he says. Sex chromosomes are often sidelined because of difficulties interpreting data, given that men possess half the number of X-linked genes as women. What’s more, random inactivation of X chromosomes makes it hard to tell how a single variant is expressed in female tissues. And the existence of pseudoautosomal regions—stretches of DNA that behave like regular chromosomes and escape inactivation—complicates matters further. © 2025 Simons Foundation

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 8: Hormones and Sex
Link ID: 29638 - Posted: 01.22.2025

By Emily Baumgaertner When President-elect Donald J. Trump mused in a recent television interview about whether vaccines cause autism — a theory that has been discredited by dozens of scientific studies — autism researchers across the country collectively sighed in frustration. But during the interview, on NBC’s “Meet The Press,” Mr. Trump made one passing comment with which they could agree: “I mean, something is going on,” he said, referring to skyrocketing rates of autism. “I think somebody has to find out.” What is going on? Autism diagnoses are undeniably on the rise in the United States — about 1 in 36 children have one, according to data the Centers for Disease Control and Prevention collected from 11 states, compared with 1 in 150 children in 2000 — and researchers have not yet arrived at a clear explanation. They attribute most of the surge to increased awareness of the disorder and changes in how it is classified by medical professionals. But scientists say there are other factors, genetic and environmental, that could be playing a role too. Autism spectrum disorder, as it is officially called, is inherently wide-ranging, marked by a blend of social and communication issues, repetitive behaviors and thinking patterns that vary in severity. A mildly autistic child could simply struggle with social cues, while a child with a severe case could be nonverbal. There is no blood test or brain scan to determine who has autism, just a clinician’s observations. Because there is no singular cause of autism, scientists say there is therefore no singular driver behind the rise in cases. But at the heart of the question is an important distinction: Are more people exhibiting the traits of autism, or are more people with such traits now being identified? It seems to be both, but researchers really aren’t sure of the math. More than 100 genes have been associated with autism, but the disorder appears to result from a complex combination of genetic susceptibilities and environmental triggers. The C.D.C. has a large-scale study on the risk factors that can contribute to autism, and researchers have examined dozens of potential triggers, including pollution, exposure to toxic chemicals and viral infections during pregnancy. © 2024 The New York Times Company

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29609 - Posted: 12.28.2024

By Grace Huckins Genes on the X and Y chromosomes—and especially those on the Y—appear to be associated with autism likelihood, according to a study focused on people who have missing or extra sex chromosomes. The findings add to the ongoing debate about whether autism’s sex bias reflects a male vulnerability, a female protective effect or other factors. “The Y chromosome is often left out of genetic discovery studies. We really have not interrogated it in [autism] studies very much,” says Matthew Oetjens, assistant professor of human genetics at Geisinger Medical Center’s Autism and Developmental Medicine Institute, who led the new work. There is a clear sex difference in autism prevalence: Men are about four times as likely as women to have a diagnosis. But uncovering the reasons for that discrepancy has proved challenging and contentious. Multiple biological factors may play a role, in addition to social factors—such as the difficult-to-measure gulfs between how boys and girls are taught to behave. Add on the possibility of diagnostic bias and the question starts to look less like a scientific problem and more like a politically toxic Gordian knot. But there are some threads that researchers can pull to disentangle these effects, as the new study illustrates. People with sex chromosome aneuploidies—or unusual combinations of sex chromosomes, such as XXY in those with Klinefelter syndrome or a single X in Turner syndrome—provide a unique opportunity to examine how adding or taking away chromosomes can affect biology and behavior. Previous studies noted high rates of autism in people with sex chromosome aneuploidies, but those analyses were subject to ascertainment bias; perhaps those people found out about their aneuploidies only after seeking support for their neurodevelopmental conditions. © 2024 Simons Foundation

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 8: Hormones and Sex
Link ID: 29596 - Posted: 12.11.2024

By Talia Barrington Growing up in England, Caragh McMurtry wasn’t your typical future Olympic rower. Born to parents who worked in a local factory, raised in low-income housing, frequently in trouble for being a “terror,” she didn’t exactly fit the mold of a sport known for a certain elitism. But when an after-school program funded by British Rowing was offered at her school, McMurtry gave it a try. With rowing, unlike at school, where she struggled to connect with peers, rules were clear. Everyone had a defined job, it was always the same, and because the rowers sat in a single row, she didn’t feel that people were looking at her. “It was cathartic,” she told me. “Pushing hard gave me that sensory feedback,” and the repetitive action was “calming.” At first, everything seemed to go well. She made it to the World Rowing Junior Championships and the under 23s and senior championships, and the medals started rolling in. But then things went a little haywire. Her coaches labeled her difficult and told her she asked too many questions and was too blunt and honest with her peers. She was diagnosed with bipolar disorder, which is known for its extreme mood swings, and she was put on lithium and a cocktail of other drugs that did not work. It would take five more years before a doctor would figure out why she struggled to connect with her teammates and others around her but was so focused, so “regulated” when it came to extreme and continued physical exertion: She had a form of autism. Experts call a key aspect of what McMurtry experiences when engaged in physical activity “hyperfocus,” and it’s an overlapping hallmark of both autism and ADHD. “People with ADHD and autism have an incredibly high ability to focus on tasks that they find interesting or stimulating,” said Laura Huckins, an associate professor of psychiatry at the Yale Center for Genomic Health. “They tend to be drawn towards professions that require or include novelty, that include regular challenges, and that require high performance under stress and pressure.”

Related chapters from BN: Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 14: Attention and Higher Cognition
Link ID: 29535 - Posted: 11.02.2024

By Teddy Rosenbluth The process for diagnosing a child with autism heavily relies on a parent's description of their child’s behavior and a professional’s observations. It leaves plenty of room for human error. Parents’ concerns may skew how they answer questionnaires. Providers may hold biases, leading them to underdiagnose certain groups. Children may show widely varying symptoms, depending on factors like culture and gender. A study published Monday in Nature Microbiology bolsters a growing body of research that suggests an unlikely path to more objective autism diagnoses: the gut microbiome. After analyzing more than 1,600 stool samples from children ages 1 to 13, researchers found several distinct biological “markers” in the samples of autistic children. Unique traces of gut bacteria, fungi, viruses and more could one day be the basis of a diagnostic tool, said Qi Su, a researcher at the Chinese University of Hong Kong and a lead author of the study. A tool based on biomarkers could help professionals diagnose autism sooner, giving children access to treatments that are more effective at a younger age, he said. “Too much is left to questionnaires,” said Sarkis Mazmanian, a microbiome researcher at the California Institute of Technology. “If we can get to something we can measure — whatever it is — that’s a huge improvement.” For decades, researchers have scoured the human genome, medical histories and brain scans for a reliable indicator of A.S.D., with limited success. The Food and Drug Administration has approved two diagnostic tests based on eye-tracking software, which Dr. Su said required significant involvement from a psychiatrist. © 2024 The New York Times Company

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 13: Memory and Learning; Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 29386 - Posted: 07.09.2024

By Charles Q. Choi The largest-yet single-cell genomics analysis reveals new details of the molecular pathways and cell types that are altered in the cortex in people with autism. The work, published last month in Science, also hints at how genes linked to the condition contribute to these brain differences. The findings are part of a package of 14 new papers from PsychENCODE, a multi-institution consortium launched in 2015 to study the molecular basis of neuropsychiatric conditions. The initiative’s latest phase of research analyzed human brains at the single-cell level instead of relying on bulk tissue samples as in previous efforts. “Single-cell analysis gives you the ability to really understand a condition in terms of cell-cell interactions, and how a condition might affect different cell types in very different ways,” says PsychENCODE chair Daniel Geschwind, professor of human genetics, neurology and psychiatry at the University of California, Los Angeles, who led the new autism study. Past work by Geschwind and others identified a “molecular signature” in tissue samples of autism brains, characterized by increased expression of immune signaling genes, decreased activity of synaptic and neuronal genes, and a reduction in the regional gene-expression patterns typically seen across the cortex. The first single-cell analysis—involving cells from 15 autistic and 16 non-autistic people, and published in 2019—hinted at a role for microglia and excitatory neurons in layer 2/3 of the cortex. The new study confirms these previous findings and expands autism’s molecular signature to include a subtype of interneurons and layer 5/6 excitatory neurons, which project to other cortical areas. It also adds gene-expression changes, such as heightened immune responses in oligodendrocytes, cells that help produce the myelin sheath insulating the central nervous system. “That suggests there may be something going on broadly with connectivity in autism,” Geschwind says. © 2024 Simons Foundation

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29371 - Posted: 06.26.2024

Jon Hamilton Scientists have found a way to restore brain cells impaired by a rare and life-threatening genetic disorder called Timothy syndrome. A type of drug known as an antisense oligonucleotide allowed clusters of human neurons to develop normally even though they carried the mutation responsible for Timothy syndrome, a team reports in the journal Nature. The approach may help researchers develop treatments for other genetic conditions, including some that cause schizophrenia, epilepsy, ADHD, and autism spectrum disorder. "It's immensely exciting because we now have the tools," says Dr. Sergiu Pasca, a professor of psychiatry and behavioral sciences at Stanford University and the study's senior author. "It's the beginning of a new era for many of these diseases that we first thought were untreatable," says Dr. Huda Zoghbi, a professor at Baylor College of Medicine who was not involved in the research. But most of these conditions involve multiple genes, not just one — and scientists don't yet know enough about these multiple gene disorders to effectively treat them with antisense oligonucleotides, Zoghbi says. Timothy Syndrome has been diagnosed in fewer than 100 people worldwide. Children born with it often have heart problems, autism, epilepsy, developmental delay, and intellectual disability. But because Timothy syndrome is caused by a mutation in a single gene, it offers scientists a way to study changes that affect brain development. "Rare syndromes that are very clearly defined genetically are sort of like windows, or Rosetta Stones, into understanding other, more common conditions," Pasca says. © 2024 npr

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29277 - Posted: 04.30.2024

By Saima S. Iqbal Before becoming a researcher, Aimee Grant worked as a caregiver for six years in Cornwall, England, supporting autistic adults in group homes. But only more than a decade later, after befriending an autistic colleague at a sociology conference, did she realize she was autistic herself. The stereotypical view of autism as a brain impairment more commonly found in men made it difficult for Grant to make sense of her internal world. From an early age, she struggled to pick up on important social cues and found the sounds and scents in her environment distractingly painful. But like many children in her generation, she says, she grew accustomed to either dismissing or disguising her discomfort. It was by listening to some of the stories of her female peers that Grant saw that the label could fit. Receiving a diagnosis in 2019 prompted her to “reframe [my] entire life,” she says. She began working with her mind rather than against it. She no longer felt the same pressure to seem as nonautistic as possible with friends and family members, and she began to make use of accommodations at work, such as a light filter for her computer monitor. Today, as a public health researcher at Swansea University in Wales, Grant aims to uncover the lived experience of autistic people. Many scientists and clinicians see autism as a developmental disorder that hinders a person’s ability to understand and communicate with others. Grant believes that their work often obscures the heterogeneity of autism. And because many studies view autism as a disease, they overlook the reality that autistic people can feel more disabled by widespread misunderstanding and a lack of accommodations than by autistic traits themselves. © Society for Science & the Public 2000–2024.

Related chapters from BN: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory and Learning
Link ID: 29261 - Posted: 04.20.2024