Research News

Scroll through recent research or click the category icon to the right of each title for similar research summaries. If you would like more background context on a particular piece of research, please click the link next to the “Reading Room Guide,” the small character at the bottom-left of each research story. He will transport you to the appropriate page in Autism Reading Room. You can access original publication sources and other popular media articles by clicking the news buttons at the bottom-right of each summary.

Are Females Protected Against Autism by Their DNA?

By Eric Larsen, Ph.D. on April 9, 2014
female protective model2

 

Background:  One of the hallmarks of Autism Spectrum Disorder (ASD) is its increased prevalence in males, with an estimated male-to-female ratio of four-to-one. Scientists hypothesize that this gender bias may be the result of the “female protective model.” According to this model, a greater extent of genetic damage is required to overcome an inherent protective mechanism in females. Subsequently, ASD is found more often in males, who require less genetic damage to trigger ASD onset.

 

What’s new:  A recent report in the American Journal of Human Genetics analyzes the genetic variation present in male and female individuals with ASD. The authors report that females with ASD possess a greater number of damaging genetic variants compared to males on the spectrum. Moreover, damaging genetic variations are inherited more often from mothers, rather than fathers.  Given that males and females have a different set of sex chromosomes (females have two X chromosomes, and males have an X an Y chromosome), the authors questioned if genetic changes to the X chromosome might put males at higher risk for ASD. They concluded, however, that genetic variation in the X chromosome made very little contribution to ASD.

 

Why it’s important:  This study strengthens the case for a “female protective model” in ASD. Future research will likely seek to understand the underlying basis for this protective effect in females. Furthermore, the findings of this study may have potential implications in the interpretation of genetic screening studies in ASD cases.


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CDC Reports ASD Rate Now 1 in 68

By Shana R. Spindler, Ph.D. on March 28, 2014
1 in 68

 

Background: Every few years, the United States Centers for Disease Control and Prevention (CDC) monitors the rate of Autism Spectrum Disorder (ASD) across the country. Participants in the CDC-funded Autism and Developmental Disabilities Monitoring (ADDM) Network collect data on 8-year-old children from a sampling of United States communities. In 2007, they published their first report, which showed that about 1 in 150 children had ASD. Since then, the rate has made a steady climb. In 2009, the number rose to 1 in 110. This was followed by 1 in 88 with ASD in the 2012 report.

 

What’s New: The CDC now reports that approximately 1 in 68 children in the United States have some form of ASD. The rate of ASD varies by community, with rates as low as 1 in 175 children in Alabama, contrasted to 1 in 45 in New Jersey. Of note, nearly half of the children with ASD had average or above average intellectual ability (IQ greater than 85), as compared to only 32 percent in 2002.

 

Why it’s important: Population-based studies are an important component of estimating ASD rates. It’s difficult to pinpoint why ASD rates are steadily increasing in the United States. Several factors may be at work, such as better detection methods, increased autism awareness, or environmental influences.


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Disorder-Specific Screening Catches More ASD Cases

By Chelsea E. Toledo, M.A. on March 20, 2014
screening tools

 

Background: The American Academy of Pediatrics recommends that physicians screen all children for autism spectrum disorder (ASD) beginning at 18 months of age (http://www.cdc.gov/ncbddd/autism/hcp-recommendations.html). However, while most pediatricians routinely administer tests for a broad spectrum of developmental disorders, very few report that they screen specifically for ASD.

 

What’s New: The February 2014 issue of the journal Autism presents a study (originally published online December 21, 2012), comparing the ability of two types of screening tools to detect ASD in young children. The researchers evaluated 52 children between 18 and 24 months of age, using the Parents Evaluation of Developmental Status (PEDS) and Modified Checklist for Autism in Toddlers (MCHAT), as well as the updated M-CHAT with follow-up interview (M-CHAT+FUI). All participants then underwent diagnostic evaluation, resulting in 30 ASD diagnoses. While the broad PEDS screening caught 17 of those cases, the M-CHAT and M-CHAT+FUI detected 28 and 27, respectively.

 

Why it’s important: From the results, the researchers concluded that a combination of broad and disorder-specific screenings provide optimum detection of ASD cases, allowing for early intervention for those children ultimately diagnosed with ASD. However, with the release of the Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition in May 2013, the diagnostic criteria for ASD shifted. Future studies will need to address how the new requirements for ASD affect the success of screening tools.


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Shared Genetics: ASD and Schizophrenia

By Eric Larsen, Ph.D. on March 6, 2014
schizophrenia_2

 

Background:  New high-throughput sequencing technologies are providing unprecedented view of the human genome. Exome sequencing—a method targeting the protein-coding part of the genome—is increasingly used to unravel genetic underpinnings of common, complex disorders such as autism and schizophrenia.

 

What’s new:  In the February 13, 2014, issue of Nature, two studies reported mutations identified in exomes of large cohorts of individuals with schizophrenia and a control population. The first study analyzed rare, disruptive mutations in the protein-coding regions of approximately 2,500 genes previously implicated in schizophrenia. The team evaluated DNA of 2,536 schizophrenia cases and 2,543 healthy individuals. The second study analyzed the exomes of 600 schizophrenia trios (affected individuals along with their parents). Both studies found mutations distributed across many genes; many of these genes share function at the neuronal synapse—where two neurons communicate.  Of particular importance, the authors demonstrated that the schizophrenia-associated genes identified in their studies overlapped with autism-associated genes.

 

Why it’s important:  These findings illustrate that many rare mutations contribute to schizophrenia.  Furthermore, genes enriched in a number of critical cellular pathways active at the neuronal synapse are preferentially targeted by rare disruptive mutations in schizophrenia. A shared genetic architecture between schizophrenia and other neurodevelopmental disorders is becoming evident.


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Bioinformatics Links ASD to Stage of Fetal Development

By Sabina Muend, PhD on February 27, 2014
interactome

 

Background: Researchers have now linked several hundred genes to Autism Spectrum Disorder (ASD). Given the large number of genetic variations implicated in ASD, it is unfeasible to understand how all of these genes—and the proteins they encode—connect using experimental techniques. Therefore, researchers use bioinformatics, the process of organizing, storing, and retrieving data for analyses. One such use of bioinformatics is to make protein networks, also known as “interactomes,” which map how proteins function together in a cell.

 

What’s new: Two recent papers, both published in the scientific journal Cell, used bioinformatics to study the timing of brain development and the parts of the brain that are most associated with ASD. In the first analysis, a collaboration of researchers from across the United States found that 13 to 24 weeks post conception is a particularly sensitive time period based on the level of ASD-related gene products in a specific type of neuron. In the second study, University of California, Los Angeles, researchers used protein interactome mapping to link ASD with specific intracellular pathways. For instance, the interactome revealed that many of the ASD-related genes are highly expressed during synaptic development—a critical process for establishing neuron communication and brain circuitry.

 

Why it’s important: Based on these studies, and others like them, bioinformatics can help us understand complex disorders as well as basic cellular functioning. In the case of ASD, protein interactomes can tweeze out sensitive stages and locations of development where the impact of ASD-related genes is the greatest. Researchers hope this information could aid in the creation of finely tuned treatments.


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Drug Sheds Light on Underlying Cause of Autism

By Shana R. Spindler, Ph.D. on February 11, 2014
bumetanide

 

Background: With so many different genetic and environmental influences on autism, researchers are seeking a common link among risk factors. One thought is that different risk factors affect neuron function through a similar mechanism. For example, during birth there are maternal hormones that help the fetus deal with the stress of delivery and prepare the brain for post-natal development. Recent research suggests that understanding the dynamics of these hormones gives significant insight into newborn brain development.

 

What’s new: An animal study demonstrated that bumetanide, a commonly used diuretic drug, alters the effect of these maternal hormones. Researchers used two animal models of autism: one genetic and one drug-induced. In each model, the rodent’s progeny failed to undergo the typical brain changes in response to the labor hormone oxytocin. However, when the researchers administered bumetanide one day before delivery, the rodent’s offspring showed normal neuron function and fewer autism-like symptoms. According to the study, bumetanide enabled specific neurons to switch from an excitatory to an inhibitory state by changing chloride levels in the neuron.

 

Why it’s important: This study sheds light on autism’s underlying mechanism, linking both genetic and environmental risk factors to oxytocin’s effect on brain changes during birth. The finding, reported in the February 7, 2014, edition of Science magazine, supports a common mechanism for autism and paves the way for novel therapeutic strategies.


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DSM-5 Criteria May Reduce ASD Prevalence, Slightly

By Shana R. Spindler, Ph.D. on January 30, 2014
DSM-5 Impact

 

Background: On May 18, 2013, the American Psychiatric Association released the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), providing guidelines for mental disorder identification. The previous version, DSM-IV-TR, used a three-domain approach to diagnose autism, including criteria for social interaction, communication deficits, and repetitive or restrictive behaviors. In contrast, the DSM-5 measures two domains—social aspects and repetitive behavior.  Moreover, DSM-5 focuses on the range of symptoms and severity under a single Autism Spectrum Disorder (ASD) compared to specific subtypes, such as Autistic Disorder and Asperger syndrome, outlined in DSM-IV.  These controversial changes have led some to question if the new version will catch all autism cases, which ultimately affects autism prevalence rates as well as access to therapy.

 

What’s new: In a population-based study, a collection of United States researchers found that DSM-5 criteria likely captures about 81 percent of existing autism cases. The researchers analyzed patient records from the Autism and Developmental Disabilities Monitoring (ADDM) network, a large multi-site surveillance system in the United States.

 

Of the 644,883 records assessed, a total of 6,577 records showed an ASD diagnosis using DSM-IV-TR criteria. When the researchers applied DSM-5 criteria to those same records, only 5339 patients still had ASD. Children with regressive history or intellectual disability and children who had originally been diagnosed by a community professional were more likely to meet all DSM-5 requirements. Surprisingly, 304 of 1020 children received an ASD diagnosis with DSM-5 criteria after narrowly missing an autism diagnosis according to DSM-IV-TR guidelines.

 

Why it’s important: Unlike previous clinic-based studies, the current study used a population-based system to examine how DSM-5 will affect autism prevalence, hopefully providing a more accurate assessment. Given that as much as 19 percent of autism diagnoses may change with the DSM-5 criteria, future studies examining changes in autism prevalence will need to take this into account.


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Empathy For Others in Pain Present in ASD

By Shana R. Spindler, Ph.D. on January 23, 2014
pain empathy_2

 

Background: Empathy is the ability to understand what another person is feeling. The lack of this trait was thought to underlie some of the social problems present in people with Autism Spectrum Disorder (ASD). However, few studies have addressed the brain activity of those with ASD in situations where empathy would be likely.

 

What’s new: On January 14, 2014, the online journal Translational Psychiatry published a study that suggests people with ASD maintain the neural ability to process empathy, at least when seeing others in pain. Researchers used functional magnetic resonance imaging to examine the spontaneous brain activity of 38 adolescents and adults with high-functioning ASD and 35 age-matched controls as they watched two-second videos of people with shoulder pain.

 

Contrary to popular belief, the individuals with ASD showed no significant difference in spontaneous brain activity upon seeing someone in pain as compared to the control group. Both groups had activity in brain areas involving emotional arousal and understanding. At a lower statistical threshold, the group with ASD appeared to have increased activity in brain areas likely used for situation assessment.

 
Why it’s important: The researchers suggest that empathy remains intact in ASD, while the perceived lack of caring links to attempts to calm personal distress by reassessing the situation. The authors of the study note that pain is a very basic social cue and that future studies should look at additional situations where empathy is used.


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Updated Screening Tool Helps Provide Early ASD Diagnosis

By Chelsea E. Toledo, M.A. on January 15, 2014
screening_3

 

Background: Early intervention has been shown to have positive outcomes for children with autism spectrum disorder (ASD). However, the disorder is typically diagnosed in children over the age of four, with an average age of diagnosis ranging from 38 to 120 months for all ASDs. During the last decade, researchers developed a screening assessment that could be administered at toddlers’ regular medical check-ups, with the aim of facilitating earlier diagnosis.

 

What’s new: On December 23, 2013, the journal Pediatrics published a study evaluating an updated version of that screening tool—called the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F). The researchers administered the 20-question checklist—which assessed children’s physical, social, and communicative habits—to parents of 16,071 children at their 18- and 24-month well-child care visits. Based on the responses, children were classified as low-, medium-, or high risk—with a follow-up questionnaire to refine the classification of those allocated to the medium-risk category. One percent of the children were ultimately deemed high-risk and were referred for further evaluation. Of those, 95 percent had confirmed developmental delays, and 47.5 percent received ASD diagnoses.

 

Why it’s important: From the results, the researchers concluded that the updated version of the M-CHAT is better at detecting ASD than its previous iteration. At the same time, the newer version of the screening tool classifies a smaller proportion of children as high- or medium-risk—reducing the number of families who would need to pursue follow-up testing.


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Blood Test Distinguishes Those with Autism

By Shana R. Spindler, Ph.D. on January 6, 2014
blood test

 

Background: Today, doctors diagnose Autism Spectrum Disorder (ASD) using behavioral evaluation, limiting how early in development a doctor can detect signs of autism. For this reason, researchers are looking for autism biomarkers, measurable features that are predictive of the disorder. One line of research investigates how much genes are turned on or off in the body. Called a “gene expression profile,” this particular measurement could distinguish children with ASD.

 

What’s new: Using DNA chip technology, researchers at Boston Children’s Hospital and Harvard Medical Center analyzed gene expression profiles in the blood cells of 20 pairs of siblings, in which only one sibling had ASD, and 18 unrelated control individuals. According to their study, 189 genes differed in expression between the affected and unaffected siblings. Surprisingly, a small group of the unaffected siblings had gene expression profiles that more closely matched the unrelated individuals than their own sibling. The genes that differed in expression are known to play a role in cell maintenance, energy production, neural signaling, immune response, and calcium signaling pathways.

 

Why it’s important: This study supports the idea that gene expression profiles  may help predict if a child will develop autism. This has implications for early diagnosis, or at the very least, the identification of children that may need closer monitoring of developmental progress. Additional studies with larger sample sizes are needed to verify the study’s findings.


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Male Folate Intake Linked to ASD-Related Gene Expression

By Chelsea E. Toledo, M.A. on December 27, 2013
folic acid father_2

 

Background: Epigenetic modifications are those that alter DNA’s properties without changing the actual sequence. These alterations make it more or less likely that a gene will be expressed. Recently, researchers have been exploring whether epigenetic information, which is influenced by environmental factors, can be passed from parents to offspring.

 

What’s New: On December 10, 2013, a study in the journal Nature Communications evaluated the role of fathers’ intake of folate—a form of vitamin B—in their offspring’s development. Researchers exposed male mice to varying levels of folate from the time they were in utero; 49 received sufficient amounts of the nutrient, and 54 were folate-deficient. After breeding them, they found that the offspring of folate-deficient mice had greater epigenetic abnormalities in the genes related to diabetes, autism spectrum disorder (ASD), schizophrenia, and cancer.

 

Why it’s important: This study suggests that a father’s diet can influence the health of his resulting children, at least in mice. While further research is needed, the findings tout proper folate intake in men as a possible factor to help prevent ASD-related gene expression in children.


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Multi-Year Study Follows Sleep Difficulties in ASD

By Shana R. Spindler, Ph.D. on December 18, 2013
sleep

 

Background: According to several studies, children with Autism Spectrum Disorder (ASD) are more likely to have sleep problems than typically developing children. These include reduced sleep, night waking, early morning waking, nightmares, and the lack of a sleep routine. It is important to understand sleep difficulties in ASD as they can negatively affect daytime behavior.

 

What’s new: In a study that followed over 10,000 English children for 11 years, researchers from the UK and Canada recorded sleep patterns of children from six to 140 months of age. Of those children, 73 were eventually diagnosed with ASD. Children with ASD slept on average 43 minutes less than typical children at 81 months of age. The decreased sleep times began around 30 to 42 months of age and lasted until adolescence.

 

Why it’s important: This study highlights the need for parents to evaluate sleep problems in children with ASD from an early age. If sleep problems persist, parents can discuss therapeutic options with their doctor.


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Oxytocin Ups Social Brain Activity in Children with ASD

By Chelsea E. Toledo, M.A. on December 10, 2013
oxytocin

 

Background: Oxytocin is a hormone most commonly associated with childbirth and lactation, and recent studies have explored its role in maternal, romantic, and social bonding. For instance, when given oxytocin through the nose, typically developing adults showed improvement in eye contact, trust, and reading emotions from facial expressions.

 

What’s New: On December 2, 2013, the Proceedings of the National Academy of Science (PNAS) published a paper exploring the cognitive effects of oxytocin in children with autism spectrum disorder (ASD). In a randomized, double-blind study, the researchers assigned 17 children aged eight to 16.5 to receive a single oxytocin nasal spray or a placebo. Brain scans of children in the treatment arm showed increased activity in certain areas of the brain when the researchers asked them to assess expression in photos of eyes. The brain areas with increased activity included those associated with motivation, higher information processing, sleep, decision-making, and social perception. Activity of the same brain areas decreased in participants who received oxytocin when they were asked to categorize images of automobiles.

 

Why it’s important: While it used a small sample size, this study demonstrates that therapeutic oxytocin might help children with ASD respond more appropriately to social versus non-social stimuli.


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Up Antioxidant Activity To Improve Behavior, Study Says

By Shana R. Spindler, Ph.D. on December 2, 2013
glutathione

 

Background: Some children with autism have deficits in antioxidant activity, which normally detoxifies cells. An antioxidant is a molecule that is capable of neutralizing damage causing free radicals—most people know of the antioxidant Vitamin C. Glutathione is another antioxidant, and it is lower in some people with autism. Antioxidant protection is critical for the immune system and neurons, which are particularly susceptible to cellular damage.

 

What’s new: Researchers at Arkansas Children’s Hospital Research Institute report that nutritional supplementation aimed at increasing glutathione activity improves autism-related behaviors. In the study, 40 children with autism who had low levels of active glutathione received supplements of methylcobalamin and folinic acid, factors in glutathione production and activation. After three months, changes in blood levels of active glutathione correlated with increased scores on behavior measurements. The children made large gains in expressive communication, daily living skills, and various social skills. Thirty-seven children completed the study with minimal side effects, mostly hyperactivity and reduced sleep.

 

Why it’s important: Two key points stand out from this study. First, antioxidant levels may serve as a useful biological marker for a subset of autism. Second, nutritional supplementation may indeed help children who fall within this category. This preliminary study warrants further investigation with a randomized, double blind trial.


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Eye Fixation is Lost, Not Absent, in ASD

By Shana R. Spindler, Ph.D. on November 15, 2013
early eye contact

 

News Brief: A new article in the high impact journal Nature has received a lot of coverage in the media recently, for good reason. United States researchers revealed that poor eye contact observed in children with Autism Spectrum Disorder (ASD) results from a gradual decline in eye fixation in two to six-month-old infants. Their findings suggest a potential window for early intervention in ASD before this social behavior is lost. It remains unclear, however, if addressing eye fixation deficits will improve other ASD-related behaviors.


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UK Autism Rates Stabilize from 2004 to 2010

By Shana R. Spindler, Ph.D. on November 5, 2013
New rates

 

Background: In several countries around the world, autism rates rose dramatically in the 1990s. In March 2012, the United States Centers for Disease Control (CDC) released results from a long-term study indicating that U.S. autism rates continued to rise—by about 78 percent—between the years 2004 and 2008. This publication prompted U.S. and United Kingdom researchers to explore autism rates in the U.K. for the same time period.
What’s new: On October 16, 2013, the online journal BMJ Open published a population-based study that looked at autism rates in the U.K. from 2004 to 2010 in 8-year-old children. Using the U.K. General Practice Research Database (GPRD), researchers found that autism prevalence remained stable during those years, even after the dramatic increase during the 1990s. Newly diagnosed cases also reached a plateau, with an average of 1.2 per 1000 boys and .23 per 1000 girls diagnosed per year across the seven years examined.

 

Why it’s important: While U.S. rates have continued to climb over the past decade, U.K. rates have appeared to stabilize. Compared to the CDC’s estimate of one in 54 boys and 1 in 252 girls with autism in the U.S., the current study suggests a lower prevalence in the U.K. at 3.8 in 1000 boys and .8 in 1000 girls. It’s important to note that differences in diagnostic criteria and study methodology may contribute to these discrepancies.


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Parent Training May Improve Autistic Children’s Diet

By Chelsea E. Toledo, M.A. on October 18, 2013
MEAL Plan

 

Background: Anecdotal evidence demonstrates that children with Autism Spectrum Disorder (ASD) often have problems maintaining a regular diet, and studies suggest that this population is at a greater risk for nutritional issues—including vitamin deficiencies, poor bone growth, and obesity.

 

What’s New: On October 7, 2013, the journal Autism published a pilot study evaluating a curriculum for parents to address feeding issues in children with ASD. The program, called the Autism MEAL Plan, was administered over eight training sessions and covered behavior management strategies, specific interventions for ASD-associated feeding issues, and tactics to promote self-feeding. 30 families began the study, completing a series of evaluations to assess dietary issues, general health, and stress experience by parents. Of the 19 families continuing on with the study, 10 completed Autism MEAL Plan training, reporting a significant reduction in parental stress as compared to the control group. However, no significant differences between groups existed regarding feeding behaviors and dietary variety following the intervention.

 

Why it’s important: This study provides preliminary evidence to support parental training programs for the sake of improving meal time for children with ASD. However, because so few families participated, further research is needed to provide conclusive results.


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Team Approach Still Gold Standard for ASD Diagnosis

By Shana R. Spindler, Ph.D. on October 10, 2013
Comprehensive

 

Background: A multidisciplinary approach that incorporates clinical evaluations and behavioral observations has been the gold standard for Autism Spectrum Disorder (ASD) diagnosis. Given the cost and time associated with multiple evaluations, researchers are investigating if a lean model of diagnosis that utilizes fewer assessments can diagnose ASD equally well.

 

What’s new: Researchers at the Gillberg Neuropsychiatry Centre in Gothenburg, Sweden, designed a study to find which autism assessments best diagnose ASD or if a multidisciplinary approach is still needed. The researchers compared independent assessments for 34 children age 24 to 46 months using psychiatric evaluation, Griffiths’ Developmental Scales, language assessment, the Diagnostic Interview for Social and Communication disorders (DISCO), the Autism Diagnostic Observation Schedule (ADOS), and preschool/home observation. After completion of the independent assessments, the clinicians held a diagnostic case conference for each child to deliver a final diagnosis.

 

Of the six assessments examined in the study, the most informative was the preschool/home observation, while the psychiatric evaluation matched poorest with the final diagnosis. No single assessment type was perfect, and this especially held true for female children. Based on the poor agreement between individual assessments, the researchers suggest that a comprehensive clinical evaluation should remain the gold standard for ASD diagnosis.

 
Why it’s important: Families and insurance providers rely on studies like these to determine which diagnostic assessments are necessary for proper care. Given the findings in this study, a comprehensive evaluation that utilizes multiple assessment types likely offers the best care to date.


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Study Examines Behavior in Older Adults with ASD

By Chelsea E. Toledo, M.A. on October 4, 2013
older adults with ASD_2

 

Background: Autism spectrum disorder (ASD) has been studied extensively in children, and is now estimated to affect one in every 88. However, relatively few have examined adults with the condition.

 

What’s New: On September 25, 2013, a study was published in the Journal of Neurodevelopmental Disorders evaluating the prevalence of clinical problems in older adults with both ASD and intellectual disabilities. Using surveys administered across states between 2009 and 2011, the researchers evaluated more than 10,000 cases of intellectual disability in adults between the ages of 30 and 59. They found that about 8 percent of study participants had ASD, and that those with both ASD and intellectual disabilities were about twice as likely—at about 50 percent—to engage in self-harm, disruptive, and destructive behaviors than their counterparts without ASD.

 

Why it’s important: This study demonstrates the need for more research focusing on adults with ASD, whose population is increasing.


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