Intellectual Disability

Do autistics struggle with driving?

Do autistics struggle with driving

In the first pilot study asking adults on the autism spectrum about their experiences with driving, researchers at Drexel University found significant differences in self-reported driving behaviors and perceptions of driving ability in comparison to non-autistic adults. As the population of adults with autism continues growing rapidly, the survey provides a first step toward identifying whether this population has unmet needs for educational supports to empower safe driving – a key element of independent functioning in many people’s lives.

“Previous research in my lab has included extensive research in driving capacity with people who have a variety of conditions such as multiple sclerosis or who had experienced traumatic brain injury,” said study co-author Maria Schultheis, PhD, an associate professor of psychology at Drexel. “When we investigate whether and under what circumstances a condition or neurological difference might affect driving ability, as a standard starting point we want to go to individuals and find out from their perspective what problems they are having on the road, in their real-world experience. That question is pivotal to shape and inform the goals of long-term research – and is especially important when we turn to look at a developmental difference like autism, where there has been too little research to establish yet whether widespread driving difficulties exist.”

Only a few previous studies have examined driving ability in individuals with autism, and those studies focused on adolescents and new drivers rather than experienced adult drivers. These studies relied on parent surveys and evaluations of discrete aspects of driving performance. The new Drexel study, published early online this month in the Journal of Autism and Developmental Disorders, used a validated survey that has been extensively used in driving research, and asked adult licensed drivers on the autism spectrum to describe their first-hand, real-world driving experiences.

“We were beginning to see discussion in the research literature that aspects of autism spectrum disorders, such as neurocognitive challenges and social recognition difficulties, could make it likely that members of this population would experience significant challenges with driving,” said the study’s lead author Brian Daly, PhD, an assistant professor of psychology in Drexel’s College of Arts and Sciences. “But that assumption hadn’t been studied in adult drivers, or based on the experiences of the drivers themselves – so these were the questions we explored.”

In this survey, adults with autism spectrum disorders reported earning their drivers’ licenses at a later age, driving less frequently and putting more restrictions on their own driving behaviors (such as avoiding driving on highways or at night), on average compared to non-autistic adults. The respondents with autism spectrum disorders also reported more traffic violations.

Because this pilot study was relatively small and based on self-reports of 78 ASD respondents and 94 non-ASD comparison participants, Schultheis and Daly noted that the differences they found were open to several possible interpretations. Autistic adults may have reported driving less often and restricting their behaviors out of self-awareness of actual difficulties or deficiencies in their driving. These difficulties and/or reduced driving exposure could also explain the higher rate of reported violations.

Alternatively, it is possible that the respondents on the autism spectrum were more honest in their answers, but no worse at driving than everyone else.

“In driving research, it’s well established that people have a positive bias when reporting their own driving skills,” said Schultheis. “Because the study relied on self-reported answers, we can’t rule out whether the respondents with autism were simply being more descriptive and honest about their difficulties than the control group.”

One intriguing finding that Daly and Schultheis noted was that the difficulties adults with autism reported were not clustered in any specific areas, such as problems related to social processing of other drivers’ or pedestrians’ expected behaviors, or difficulties with neurocognitive aspects of driving such as motion perception and reaction time.

“It suggests that the challenges these individuals are facing are more global than specific,” Daly said.

“This is such an important study,” said Paul Shattuck, PhD, an associate professor and director of the research program area in life course outcomes at the A.J. Drexel Autism Institute, who was not involved in conducting the study. “Cognitively-able adults on the autism spectrum face many barriers to full participation in society. Facilitating access to transportation options will increase the capacity for these adults to contribute to their communities.”

Daly and Schultheis are continuing to investigate driving behavior in adults with autism through further research, with funding from the A.J. Drexel Autism Institute, the first autism research center focused on a public health science approach. In the next phase of research, the team is using driving simulation in Schultheis’ lab to objectively capture aspects of actual driving performance in adults on the autism spectrum. Individuals interested in enrolling in these studies should contact schultheis@drexel.edu.

“This is a first step toward identifying, categorizing and quantifying challenges that may exist in this population,” Schultheis said. “What we find will help determine what needs there may be for interventions, from driver education programs to different kinds of training exposures.”

Source: eureka alert

Autism and intellectual disability incidence linked with environmental factors

An analysis of 100 million US medical records reveals that autism and intellectual disability (ID) rates are correlated at the county level with incidence of genital malformations in newborn males, an indicator of possible congenital exposure to harmful environmental factors such as pesticides. Autism rates — after adjustment for gender, ethnic, socioeconomic and geopolitical factors — jump by 283 percent for every one percent increase in frequency of malformations in a county. Intellectual disability rates increase 94 percent. Slight increases in autism and ID rates are also seen in wealthier and more urban counties.

The study, published by scientists from the University of Chicago March 13 in PLOS Computational Biology, confirms the dramatic effect of diagnostic standards. Incidence rates for Autism and ID on a per-person basis decrease by roughly 99 percent in states with stronger regulations on diagnosis of these disorders.

“Autism appears to be strongly correlated with rate of congenital malformations of the genitals in males across the country,” said study author Andrey Rzhetsky, PhD, professor of genetic medicine and human genetics at the University of Chicago. “This gives an indicator of environmental load and the effect is surprisingly strong.”

Although autism and intellectual disability have genetic components, environmental causes are thought to play a role. To identify potential environmental links, Rzhetsky and his team analyzed an insurance claims dataset that covered nearly one third of the US population. They used congenital malformations of the reproductive system in males as an indicator of parental exposure to toxins.

Male fetuses are particularly sensitive to toxins such as environmental lead, sex hormone analogs, medications and other synthetic molecules. Parental exposure to these toxins is thought explain a large portion of congenital reproductive malformations, such as micropenis, hypospadias (urethra on underside of the penis), undescended testicles and others.

The researchers created a statistical baseline frequency of autism and ID across the country. They then looked at the actual rates of these disorders, county-by-county. Deviations from the baseline are interpreted as resulting from local causes. Factors such as age, ethnicity, socioeconomic groups and geopolitical statuses were analyzed and corrected for.

The team found that every one percent increase in malformations in a county was associated with a 283 percent increase in autism and 94 percent increase in ID in that same county. Almost all areas with higher rates of autism also had higher rates of ID, which the researchers believe corroborates the presence of environmental factors. In addition, they found that male children with autism are almost six times more likely to have congenital genital malformations. Female incidence was linked with increased malformation rates, but weakly so. A county-by-county map of autism and ID incidence above or below the predicted baseline for the entire US is included in the study.

Non-reproductive congenital malformations and viral infections in males were also associated with double digit increases in autism and ID rates. Additionally, income appeared to have a weak effect — every additional $1,000 of income above county average was correlated with around a three percent increase in autism and ID rates. An increased percentage of urban population in a county also showed a weak increase in rates.

The most striking negative effect was state regulation. State-mandated diagnosis of autism by a clinician for consideration in special education was linked with around a whopping 99 percent decrease in the rate of incidence for autism and ID. Certain ethnic backgrounds, such as pacific islanders had significantly lower risk for both diseases.

While the effect of vaccines was not analyzed as part of this study, Rzhetsky notes that the geographic clustering of autism and ID rates is evidence that if vaccines have a role, it’s a very weak one as vaccinations are given uniformly across the US.

Rzhetsky acknowledges there are potential confounders to the study, for example ease of access to data could differ between counties or uneven genetic distribution, beyond the factors they controlled for, could have an effect. The team anticipates future studies could leverage data from the Environmental Protection Agency and other sources to identify links between specific environmental causes and increased rates of autism and ID.

“We interpret the results of this study as a strong environmental signal,” Rzhetsky said. “For future genetic studies we may have to take into account where data were collected, because it’s possible that you can get two identical kids in two different counties and one would have autism and the other would not.”

Source: escience news

 

FDA approves post-natal test to help diagnose developmental delays

The US Food and Drug Administration has authorized for marketing the Affymetrix CytoScan Dx Assay, which can detect chromosomal variations that may be responsible for a child’s developmental delay or intellectual disability. Based on a blood sample, the test can analyse the entire genome at one time and detect large and small chromosomal changes.

According to the National Institutes of Health and the American Academy of Paediatrics, two to three per cent of children in the United States have some form of intellectual disability. Many intellectual and developmental disabilities, such as Down syndrome and DiGeorge syndrome, are associated with chromosomal variations.

“This new tool may help in the identification of possible causes of a child’s developmental delay or intellectual disability, allowing healthcare providers and parents to intervene with appropriate care and support for the child,” said Alberto Gutierrez, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Centre for Devices and Radiological Health. “The FDA’s review of the test provides clinical laboratories with information about the expected performance of the device and the quality of the results.”

The FDA reviewed the Affymetrix CytoScan Dx Assay through its de novo classification process, a regulatory pathway for some novel low-moderate-risk medical devices.

For the de novo petition, the FDA’s review of the CytoScan Dx Assay included an analytical evaluation of the test’s ability to accurately detect numerous chromosomal variations of different types, sizes, and genome locations when compared to several analytically validated test methods. The FDA found that the CytoScan Dx Assay could analyse a patient’s entire genome and adequately detect chromosome variations in regions of the genome associated with intellectual and developmental disabilities.

Additionally, the agency’s review included a study that compared the performance of the CytoScan Dx Assay to tests that are commonly used for detecting chromosomal variations associated with a developmental delay or intellectual disability. A comparison of test results from 960 blood specimens showed the CytoScan Dx had improved ability over commonly used tests, including karyotyping and FISH chromosomal tests, to detect certain chromosomal abnormalities.

This device should not be used for stand-alone diagnostic purposes, pre-implantation or prenatal testing or screening, population screening, or for the detection of, or screening for acquired or genetic aberrations occurring after birth, such as cancer. The test results should only be used in conjunction with other clinical and diagnostic findings, consistent with professional standards of practice, including confirmation by alternative methods, evaluation of parental samples, clinical genetic evaluation, and counselling as appropriate, according to a statement issued by the FDA.

Interpretation of test results is intended to be performed only by healthcare professionals who are board certified in clinical cytogenetics or molecular genetics, the statement said.

Affymetrix CytoScan Dx Assay is manufactured by Affymetrix, Inc, located in Santa Clara, California.

Source: India Medical Times