The Prevalence of Broad Autism Phenotype in Young Adults: The Roles of Genetic Relationship to Autism, Gender, and Academic Major

Subclinical levels of autism traits are known as the Broad Autism Phenotype (BAP) and include a rigid personality, aloof personality, and pragmatic language difficulties. Genetic relatives of children with autism spectrum disorder (ASD), males, and those in math- or science-oriented careers may be more likely to exhibit BAP. This study examined the prevalence of BAP in young adults to assess the influence of genetic relationship to ASD, gender, and academic field. Online self-report data from 170 undergraduate college students included the Broad Autism Phenotype Questionnaire (BAPQ), information about genetic relationship to ASD, and demographic information. Results showed no relationship between BAP and level of shared ASD genes, gender, or academic major. However, 25.3% of our college-aged sample met BAP cutoffs, compared to previous estimates of only 5-9% of adult parents of neurotypical children and 14-23% of parents of children with ASD. These findings expand our understanding of subclinical autistic traits in young adults. This research highlights the need to investigate community-based samples of various age groups when estimating the prevalence of BAP to better-understand the extent to which these personality characteristics are present in the general population.

Sex differences in the diagnosis of autism spectrum disorder and effects of comorbid mental retardation and attention-deficit hyperactivity disorder

BACKGROUND/PURPOSE

The association between sex and diagnostic behavior of autism spectrum disorder (ASD), and the effects of comorbid mental retardation (MR) and attention-deficit hyperactivity disorder (ADHD), were explored.

METHODS

Based on the Taiwan Longitudinal Health Insurance Database (LHID)-2000 and data from 1996 through 2008, the cumulative incidence of ASD over time was compared between the sexes (both cohorts n = 38,117) using the log-rank test. The effects of comorbid MR and ADHD on the incidence of ASD were evaluated using Cox proportional hazard regression analysis. The age at first diagnosis of ASD in the two sexes was compared using the independent-sample t-test.

RESULTS

The incidence was higher in males than in females (0.0007 vs. 0.0002) across ages. Comorbid MR or ADHD increased the incidence of ASD in both sexes; comorbid MR or ADHD also decreased the male to female hazard ratio of ASD, with no significant differences in the incidence density of ASD between sexes. ADHD delayed diagnosis in both sexes (males: 6.61 vs 5.10, p < 0.0001; females: 6.83 vs 4.69, p = 0.0037).

CONCLUSIONS

The general concept of a higher incidence of ASD among males was noted in this study of a Taiwanese population, but disappeared in those with comorbid MR or ADHD, indicating unique vulnerabilities to MR/ADHD or under-identification of high-functioning females with ASD in childhood. Increasing the diagnostic sensitivity of ASD in those with comorbid ADHD is important due to a delayed diagnostic age in this group.

Comparison of the Modified Checklist for Autism in Toddlers, Revised with Follow-Up (M-CHAT-R/F) Positive Predictive Value by Race

The Modified Checklist for Autism in Toddlers, Revised, with Follow-Up (M-CHAT-R/F) is the most widely used screener for ASD. Despite the comparable rate of ASD in Black and White children, the M-CHAT-R/F was validated on a primarily White, Non-Hispanic sample. Few studies have assessed whether the screener performs adequately with racial minorities. This study compared the M-CHAT-R/F Positive Predictive Value (PPV), for ASD, and for any developmental condition, in Black and White children. We also examined M-CHAT-R/F item-level PPV by race. The PPVs for ASD and other developmental disorders were similar in both racial groups for total score and individual items. Therefore, our findings support the use of the M-CHAT-R/F with Black and White children.

Testing a Tailored Social-Ecological Model for Autism Spectrum Disorders

OBJECTIVE

To propose a tailored social ecological model for Autism Spectrum Disorders and explore relationships between variables in a large nationally-representative dataset.

METHODS

A tailored social-ecological model was developed and examined across variables in the 2016/2017 National Survey of Children's Health. A series of iterative multivariable logistic regressions were performed including individual, family, and community/neighborhood variables. A multivariable logistic regression using state-level fixed effects was performed to understand dynamics related to macro-level policies.

RESULTS

In the full model, gender, disability severity, certain types of insurance coverage and household income were significantly related to ASD diagnosis. Females had lower odds of a diagnosis compared to males (aOR: 0.27; CI:0.18-0.41). Children with at least one other moderate/severe disability had odds 7.61 higher (CI:5.36-10.82) of a diagnosis than children without moderate/severe disabilities. Children with public insurance only (aOR:1.66; CI:1.14-2.41) or both private and public insurance coverage (aOR: 2.62; CI:1.6-4.16) had higher odds of a diagnosis compared to children with private insurance only. For those who reported it was "somewhat" or "very often" hard to cover basics with their income, odds of a diagnosis were higher compared to those who reported it was "never" or "hardly ever" hard to cover basics (aOR: 1.676; CI:0.21-2.56).

CONCLUSIONS FOR PRACTICE

Patterns of ASD diagnosis are related to individual and family characteristics. There is some evidence that a child's environment has some relationship to reported ASD diagnosis. Professionals should be aware of an individual's environmental factors or context when assessing for ASD.

Association between neighbourhood socioeconomic status and developmental vulnerability of kindergarten children with Autism Spectrum Disorder: A population level study

There is limited knowledge about the relationship between neighbourhood socioeconomic status (SES) and development of kindergarten children with ASD. The primary objective of this study was to determine the association between neighbourhood SES and developmental vulnerability of kindergarten children with ASD while controlling for family SES across 10 provinces and territories in Canada. This study used data from a population level database of child development in kindergarten, collected with the Early Development Instrument (EDI). The EDI covers five broad domains of developmental health: physical health and well-being, social competence, emotional maturity, language and cognitive development, and communication skills and general knowledge. Neighbourhood SES was assessed with an SES index created using 10 variables from the 2011 Canadian Census and 2010 Taxfiler data. Family SES was assessed using 4 variables from the 2016 Canadian Census. Descriptive statistics and regression-based models were used in this study. Multilevel binary logistic regression analyses were used to examine the association between neighbourhood SES and child developmental vulnerability (yes/no), at the individual level, while controlling for family SES, demographic characteristics, and neighbourhood clustering. The association between neighbourhood SES and child developmental vulnerability at the individual level, while controlling for family SES and demographic characteristics was examined with binary single level logistic regression analyses. Multivariable linear regression analyses were used to examine the association between neighbourhood SES and developmental vulnerability at the neighbourhood level (% of kindergarten children with ASD demonstrating developmental vulnerability in a neighbourhood). In Ontario, British Columbia, Manitoba, and Newfoundland and Labrador, higher neighbourhood SES was associated with lower likelihood of developmental vulnerability. In Nova Scotia, higher neighbourhood SES was associated with higher likelihood of vulnerability in the social competence and communication skills and general knowledge domains. These findings emphasize the importance of addressing neighbourhood deprivation to support the development of children with ASD. Additionally, the inconsistency highlights the importance of examining the mechanisms through which neighbourhood SES impacts development of these children on a provincial basis.

School-Based Autism Rates by State: An Analysis of Demographics, Political Leanings, and Differential Identification

We reviewed federal special education data to determine school-identified prevalence of Autism Spectrum Disorder (ASD) and other disability categories by U.S. state. We also examined whether state-level policies, demographic factors, and rates of other eligibility categories are predictive of these state ASD rates. Results indicate that overall, 1 of 81 school-aged children are served under an ASD special education eligibility. State-level demographic factors, such as socioeconomic status and political leanings were highly predictive of rates of ASD. States with higher rates of ASD had lower rates of intellectual and learning disabilities, but higher rates of Other Health Impairment (OHI).

Autism spectrum disorder/Takiwātanga: An Integrated Data Infrastructure-based approach to autism spectrum disorder research in New Zealand

New Zealand has few estimates of the prevalence of autism spectrum disorder and no national registry. The use of administrative data sources is expanding and could be useful in autism spectrum disorder research. However, the extent to which autism spectrum disorder can be captured in these data sources is unknown. In this study, we utilised three linked administrative health data sources from the Integrated Data Infrastructure to identify cases of autism spectrum disorder among New Zealand children and young people. We then investigated the extent to which a range of mental health, neurodevelopmental and related problems co-occur with autism spectrum disorder. In total, 9555 unique individuals aged 0–24 with autism spectrum disorder were identified. The identification rate for 8-year-olds was 1 in 102. Co-occurring mental health or related problems were noted in 68% of the autism spectrum disorder group. The most common co-occurring conditions were intellectual disability, disruptive behaviours and emotional problems. Although data from the Integrated Data Infrastructure may currently undercount cases of autism spectrum disorder, they could be useful for monitoring service and treatment-related trends, types of co-occurring conditions and for examining social outcomes. With further refinement, the Integrated Data Infrastructure could prove valuable for informing the national incidence and prevalence of autism spectrum disorder and the long-term effectiveness of clinical guidelines and interventions for this group.

Employment Outcomes After a Birth of a Child with a Developmental Disability: A National Nested Case-Control Study

Using records from the National Insurance Institute of Israel, we recognized all children with autism spectrum disorders (ASD, N = 8072) or hearing loss (HL, N = 2231) born in Israel between 2005 and 2010. Typical developed children were taken from a random 20% sample of children born during the same years (N = 227,492). Analyses were adjusted for year of birth, population group, parental ages, parental education, child birth order and peripherality. Working women, who gave birth to children with either ASD or HL, were at increased risk of not maintaining their working status over the 5 years after birth. There is a decreased ratio between household wage after and before birth, in families with children with either ASD or HL.

A High Prevalence of Autism Spectrum Disorder in Preschool Children in an Immigrant, Multiethnic Population in Sweden: Challenges for Health Care

This study examines the prevalence of autism spectrum disorder (ASD) in preschool children in an immigrant population. Possible risk factors for ASD and individual needs for the children and their families are described, as well as implications for health care. The estimated minimum prevalence for ASD in the area was 3.66% for children aged 2–5 years. Multiple risk factors and extensive individual needs for the children and their families were observed. The high prevalence of ASD and the plethora of needs in immigrant communities pose challenges for health care. A coordinated health care system is necessary to meet the many and individual needs.

Objective Estimates of Direct-Medical Costs Among Persons Aged 3 to 38 Years With and Without Research-Defined Autism Spectrum Disorder Ascertained During Childhood: A Population-Based Birth-Cohort Study

OBJECTIVES

Accurate estimates of autism spectrum disorder (ASD)-associated medical costs are essential for predicting future care needs, allocating resources, identifying best practices, and modeling cost-effectiveness. Most existing studies have either employed subjective cost data or ascertained ASD using self-reported or International Classification of Diseases-coded diagnoses. Such ascertainment is especially problematic for identifying milder ASD among older individuals never diagnosed with ASD.

METHODS

This 1976 through 2000 population-based birth-cohort study was set in Olmsted County, Minnesota. ASD cases and age- and sex-matched unaffected controls were identified by applying uniform operational research criteria for ASD (using the guidelines of the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision) after rigorous review of provider-linked medical and public, private, or home school records available for all members from birth to a maximum age of 21 years. Medical cost estimates for the 901 case-control pairs used line-item provider-linked billing data (including all payers) from 2003 through 2014 (ages 3-38 years). Outpatient pharmaceutical costs were unavailable. Temporal changes in diagnostic criteria, clinical practice, public awareness, and access were addressed by separating analyses into 5-year age group and 4-year calendar period cells. Unadjusted and adjusted (age and age plus co-occurring conditions) cost estimates were provided for cases, controls, and case-control differences. Additional factors (co-occurring conditions, percentage hospitalized, intellectual disability) were investigated using unadjusted descriptive analyses.

RESULTS

Cell sample sizes ranged from 93 to 402 for age groups 3 through 19 years and from 45 to 395 for age groups 20 through 38 years. Unadjusted, age-adjusted, and fully adjusted medical costs were significantly higher for cases versus controls in 100% of cells for age groups 3 through 19 years and in 50% (unadjusted), 38% (age adjusted), and 12% (fully adjusted) of cells for age groups 20 through 38 years.

CONCLUSIONS

These unique estimates can help inform the construction of cost-effectiveness models; decisions by payers, providers, and policy makers; and predictions of lifetime costs.

Racial Disparities in a Sample of Inpatient Youth with ASD

Although more than one in 10 youth with Autism Spectrum Disorder (ASD) is admitted to a psychiatric facility before they reach adulthood, the inpatient population is underrepresented in research. Furthermore, Black youth are more likely to be psychiatrically hospitalized, compared to their White counterparts. Yet, prior research has been inconsistent in potential racial differences in ASD symptoms and severity. This study examined differences in the symptom presentation of psychiatrically hospitalized Black and White youth with ASD. Researchers collected data as part of a larger study of youth admitted to one of six US specialized inpatient psychiatric units between 2013 and 2017. We used bivariate and multivariate models to analyze the data. The study included 654 youth diagnosed with ASD, with an average age of 13 years. While bivariate analyses found that Black youth had lower written language and daily living skills and more impaired social affect and inappropriate speech, multivariate regression models suggested that overall ability level and age may be driving these differences. Specifically, the only variables that significantly predicted adaptive functioning (written language, daily living) and behavioral profiles (social affect, inappropriate speech) were verbal ability, IQ, and age. Race was not a significant predictor in any of the models. Cultural diversity and competency are vital to the identification and treatment of ASD clinical care. Thus, understanding the role race may play in early detection and accurate diagnosis is important to improving ASD identification, diagnosis, and treatment. Autism Res 2020, 13: 532-538. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study examined differences in autism symptoms between Black and White youth in psychiatric hospitals. We found that while it initially appeared that Black and White youth differed in written language and daily living skills, these racial differences were not significant once we accounted for differences in IQ, age, and verbal ability. Our findings suggest that providers should pay greater attention to other potential reasons for racial disparities in autism services.

Genetic landscape of autism spectrum disorder in Vietnamese children

Autism spectrum disorder (ASD) is a complex disorder with an unclear aetiology and an estimated global prevalence of 1%. However, studies of ASD in the Vietnamese population are limited. Here, we first conducted whole exome sequencing (WES) of 100 children with ASD and their unaffected parents. Our stringent analysis pipeline was able to detect 18 unique variants (8 de novo and 10 ×-linked, all validated), including 12 newly discovered variants. Interestingly, a notable number of X-linked variants were detected (56%), and all of them were found in affected males but not in affected females. We uncovered 17 genes from our ASD cohort in which CHD8, DYRK1A, GRIN2B, SCN2A, OFD1 and MDB5 have been previously identified as ASD risk genes, suggesting the universal aetiology of ASD for these genes. In addition, we identified six genes that have not been previously reported in any autism database: CHM, ENPP1, IGF1, LAS1L, SYP and TBX22. Gene ontology and phenotype-genotype analysis suggested that variants in IGF1, SYP and LAS1L could plausibly confer risk for ASD. Taken together, this study adds to the genetic heterogeneity of ASD and is the first report elucidating the genetic landscape of ASD in Vietnamese children.

Multi-stage Screening in Early Intervention: A Critical Strategy for Improving ASD Identification and Addressing Disparities

Health disparities in ASD detection affect children's access to subsequent interventions. We examined potential disparities in implementation of a multi-stage ASD screening and diagnostic evaluation protocol in Part C Early Intervention with 4943 children ages 14-36 months (mean 22.0 months; 62.9% boys, 73.3% children of color, 34.9% non-English-primary language, 64.5% publicly-insured). Participation and follow-through were high (64.9% and 65.3% at first- and second-stage screening, respectively, 84.6% at diagnostic evaluation). Logistic regressions identified predictors of screening participation and outcomes at each stage; demographic differences (race, language, public insurance) were observed only at first-stage screening and reflected higher participation for children of color and higher positive screens for publicly-insured children. Results suggest the multi-stage screening protocol shows promise in addressing disparities in early diagnosis.

Providers' Guidance to Parents and Service Use for Latino Children With Developmental Disabilities

To better understand disparities between Latino and White children with autism or other developmental disabilities (ASD/DD), we examined whether Latino ethnicity predicted the number of specialty care services received by children with severe functional limitations depending on medical providers' responses to parents' initial concerns about their child's development. Through linkage of the Pathways and NS-CSHCN datasets, we found ethnic disparities in the receipt of specialty services associated with providers' responsiveness to parent-reported concerns among children with ASD/DD. Among children with significant functional limitations, Latino children whose parents received passive/reassuring responses from their providers were less likely to receive specialty services than White children with ASD/DD. Providers' guidance to parents may be a promising point of intervention for future disparity reduction efforts.

Neighbourhood-level prevalence of teacher-reported Autism Spectrum Disorder among kindergarten children in Canada: A population level study

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Number of children with ASD per neighbourhood varies from none to as high as 21.

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Developmental vulnerabilities were not associated with levels of clustering.

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Highest level of clustering of children with ASD was found in Nova Scotia.

Autism in India: a case-control study to understand the association between socio-economic and environmental risk factors

Autism spectrum disorder is a neurodevelopmental disorder and the cause of autism is still unclear. The aim of this study was to investigate the association of socioeconomic, environmental, pregnancy and newborn-related risk factors among children with autism spectrum disorders. This was a population-based case-control study. The study included 55 children with autism spectrum disorder and 55 age and sex matched typically developing normal children (TD) between 3 and 12 years. Several socio-economic factors, environmental factors, pregnancy related, natal, post-natal factors and the first noticed signs by the parents were analyzed. Chi-square test was used to compare nominal variables. For multivariate analysis, forward stepwise logistic regression model was employed to examine the association between autism and the chances that the child develops ASD to assess the odds ratios. Male predominance was observed in the study. Logistic regression model showed statistical significance of the following factors: paternal age greater than 40 years, family history of autism, nutrition during pregnancy, mode of labor, fetal hypoxia, NICU stay and history of breast feeding. In this epidemiological study of autism in Coimbatore city, we found correlation between several environmental factors during fetal development and can be transmitted to succeeding generations, causing atypical behavior phenotypes. The exact exposure magnitude, exposure time in relation to vital developmental periods need to be studied to understand the influence of socioeconomic and environmental factors, which can be improved to prevent ASD-related challenges.

Caregiver Voices: Cross-Cultural Input on Improving Access to Autism Services

Decades of research have established that racial ethnic minority, low-income, and/or non-English speaking children with autism spectrum disorder (ASD) are diagnosed later than white children, and their families experience greater difficulty accessing services in the USA. Delayed access to timely diagnosis and early intervention may impact child outcomes and family quality of life. Despite their cognition of these disparities and their significant impact on the lives of those affected, explanations for the barriers experienced by underserved families are elusive, likely due to the complex interaction between structural and family factors. This study used qualitative methods to gather family and provider perspectives of perceived barriers and facilitators to obtaining an ASD diagnosis and accessing ASD-related services for underserved families. Themes from focus groups and interviews with families from three cultural groups (black, Hispanic/Latino, and Korean) and three primary languages (English, Korean, and Spanish) highlight specific barriers related to family, community, and systemic challenges as well as facilitators to accessing care for these populations. Family experiences are expanded upon with viewpoints from the providers who work with them. Recommendations are made for reducing disparities in the existing ASD service system including increasing professional, family, and community education; increasing culturally responsive care; improving provider-family partnerships; and addressing practical challenges to service access.

Incidence time trends and socioeconomic factors in the observed incidence of autism spectrum disorder in israel: A nationwide nested case-control study

Autism spectrum disorder (ASD) trends have been gaining a great deal of focus in recent decades, as many studies worldwide show a continued rise in incidence rates. Many researchers have begun analyzing socioeconomic data in relation to ASD in an effort to understand the source of these changing rates and the role of awareness and access to resources. In this study, we aim to contribute to this body of knowledge by examining incidence time trends of ASD in Israel according to socioeconomic factors. While similar studies have been conducted in Israel, this study is the first of its kind to include the total population. Individual-level data from the Israeli National Insurance Institute were used to determine cumulative incidence of ASD, first for the total population, and then stratified by population group and income categories. Multivariable logistic regression models were fit to analyze associations between income category and both risk of ASD and risk of ASD diagnosis in later age. A total of 431,348 children were examined in this study, with 13,841 cases of ASD. The cumulative incidence of all children aged 8 in 2015 was 0.64%, marking an increase compared to previous literature from Israel. Within our study period, ASD incidence followed this increase until the 2009 birth cohort, where it began to stabilize. Our initial findings from regression models showed strong positive associations between household income and ASD incidence, as expected. After factoring in population group, however, the elevated ASD incidence rates in the highest income bracket decreased. Autism Res 2019, 12: 1870-1879. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: This study contributes comprehensive and current data on ASD trends overtime in Israel and introduces crucial insights regarding the impact of socioeconomic factors on ASD diagnoses. We found a rise in ASD that began leveling off in 2009. We identified more ASD diagnoses occurring in families with higher incomes and in the General Population, pointing to the important role of sociodemographic factors on ASD diagnoses.

Ethical Challenges in Participatory Research With Autistic Adults in Israel

Contemporary calls for participatory research raise unique ethical questions. Our semi-participatory mixed-methodology study of the needs of autistic adults in Israel utilized an advisory committee of autistic persons. This article discusses three fundamental ethical issues that emerged in the study. First, employing formal diagnosis and legal guardian approval as inclusion criteria may result in the unjust exclusion of self-diagnosed autistics and those who are cognitively able to consent and participate. Second, adopting a participatory research approach does not in itself guarantee participatory justice; the representation of diverse groups from the community must be ensured. Finally, regarding autism spectrum disorder (ASD) as a medical diagnosis requires indisputable confidentiality which may conflict with the personal choice to waive anonymity and be recognized by name. Researchers and ethical committees should take these ethical challenges into account when conducting and reviewing studies with and about autistic adults.

The Role of Demographics in the Age of Autism Diagnosis in Jerusalem

Early diagnosis of autism spectrum disorder (ASD) in children enables earlier access to services and better ability to predict subsequent development. A vast body of literature consistently shows discrepancies in the age of diagnosis between children from varying socio-economic levels, cultural and ethnic backgrounds. The present study examines the effect of sociodemographic factors on age of ASD diagnosis among the three primary ethnic sectors in Jerusalem region: secular and modern religious Jews, ultra-Orthodox Jews and Arabs. Findings indicate minimal differences in age of diagnosis prior to the age of six, although Arab children of this age were largely minimally verbal. After age six, no Arab children were referred for an evaluation.

Using latent class analysis to identify treatment-use subgroups among parents of children with autism spectrum disorder

Among parents of 2,582 children (ages 4-17 years old) with autism spectrum disorder (ASD), we used latent class analysis to identify subgroups and profiles of treatment users and included annual household income in the specification of the models, then described characteristics of each subgroup. Based on three indicators of fit (Akaike's Information Criterion, Bayesian Information Criterion, and Lo-Mendell-Rubin), six latent classes of treatment users emerged. Subgroups included users of: (a) mostly private and school speech and occupational therapies; (b) nearly all treatment types; (c) mostly speech and occupational therapies, plus intensive behavioral and "other" treatments, but little medication use; (d) private therapies almost exclusively; (e) primarily psychotropic medications; and (f) mostly school-based therapies. Income significantly predicted class differences for all but one latent class. Probabilities of families' lifetime use of nine treatment types varied depending on latent classification. Proportions of families reporting having observed children's developmental regression were largest in those with the highest overall treatment use, and these children also had the lowest cognitive and adaptive-functioning scores and the highest ASD symptom scores. Understanding patterns of treatment use among families of children with ASD is an important first step in enhancing treatment-related selection and implementation. Autism Research 2019, 12: 843-854. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We identified six different groups of treatment users to help explain patterns in treatment implementation among parents of children and adolescents with autism. These included families who used: (a) mostly used private and school speech and occupational therapies; (b) nearly all treatment types (private and school therapies, intensive behavioral, biomedical, psychotropic medications, and other treatments); (c) mostly speech and occupational therapies, plus intensive behavioral and "other" treatments, but little medication use; (d) private therapies almost exclusively; (e) primarily psychotropic medications; and (f) mostly school-based therapies.

Differences in Developmental Concerns of Young Children with Autism Spectrum Disorder Across Racial/Ethnic Groups

PURPOSE

Parents/caregivers of children with autism spectrum disorder (ASD) have varying types of initial concerns regarding their child's development, which may be culturally bound to parents' perceptions of their child's development. This study investigated differences in the types of initial developmental concerns reported by parents or caregivers of different racial/ethnic groups with children in an early intervention program.

METHOD

This study examined the frequency of endorsement of different types of concerns in African American, Caucasian, and Hispanic families.

RESULTS

No significant differences between racial/ethnic groups were found in the endorsement of concerns related to communication, language/speech, motor, problem behavior, sensory, feeding, prematurity, attention, adaptive functioning, and medical conditions. Racial/ethnic groups differed significantly in their endorsement for social concerns.

CONCLUSION

Racial/ethnic group differences were confirmed regarding initial developmental concerns related to social behavior, which may be due to cultural beliefs. The implications of these findings on early identification are discussed.

Geographic Disparities in Treatment for Children with Autism Spectrum Disorder

OBJECTIVE

Geographic differences may provide insight into what factors influence the likelihood that a child is diagnosed with autism spectrum disorder (ASD) in the United States; yet, there have been few nationally representative surveys that have explored this topic. The current study expands the limited literature by analyzing regional differences in ASD prevalence, service utilization, and the presence of unmet needs within a nationally representative sample of children.

METHODS

Data were drawn from the 2014-2016 National Health Interview Survey (NHIS), a nationally representative household survey of the noninstitutionalized US population. Children 3 to 17 years of age were included in the analytic sample. Prevalence estimates accounted for the complex survey design of the NHIS, and differences between geographic regions were compared using logistic/linear regressions with and without adjustment for child/family characteristics.

RESULTS

The prevalence of ASD was highest in the Northeast (3.0%), followed by the Midwest (2.4%), South (2.4%), and West (2.3%). A significant difference was found between the Northeast and West (P < .05); however, after accounting for child and family characteristics, this difference was no longer significant. Children with ASD in the Northeast were the most likely to have seen a specialist in the past year. Approximately 1 in 8 children with ASD experienced at least 1 unmet need, but there were no differences found by geographic region.

CONCLUSIONS

Although differences in prevalence were not significant after adjustment, service utilization differences remained. It appears that children with ASD in the Northeast utilize the greatest number of specialty services when compared to children with ASD from other parts of the country.

Maternal smoking during pregnancy and autism: using causal inference methods in a birth cohort study

An association between maternal smoking in pregnancy and autism may be biologically plausible, but the evidence to date is inconsistent. We aimed to investigate the causal relationship between maternal smoking during pregnancy and offspring autism using conventional analysis and causal inference methods. In the Avon Longitudinal Study of Parents and Children we investigated the association of maternal smoking during pregnancy (exposure) with offspring autism spectrum disorder (ASD) or possible ASD diagnosis (n = 11,946) and high scores on four autism-related traits (outcomes) (n = 7402-9152). Maternal smoking was self-reported and also measured using an epigenetic score (n = 866-964). Partner's smoking was used as a negative control for intrauterine exposure (n = 6616-10,995). Mendelian randomisation (n = 1002-2037) was carried out using a genetic variant at the CHRNA3 locus in maternal DNA as a proxy for heaviness of smoking. In observational analysis, we observed an association between smoking during pregnancy and impairments in social communication [OR = 1.56, 95% CI = 1.29, 1.87] and repetitive behaviours, but multivariable adjustment suggested evidence for confounding. There was weaker evidence of such association for the other traits or a diagnosis of autism. The magnitude of association for partner's smoking with impairments in social communication was similar [OR = 1.56, 95% CI = 1.30, 1.87] suggesting potential for shared confounding. There was weak evidence for an association of the epigenetic score or genetic variation at CHRNA3 with ASD or any of the autism-related traits. In conclusion, using several analytic methods, we did not find enough evidence to support a causal association between maternal smoking during pregnancy and offspring autism or related traits.

Self-reported sex differences in high-functioning adults with autism: a meta-analysis

Background

Sex differences in autistic symptomatology are believed to contribute to the mis- and missed diagnosis of many girls and women with an autism spectrum condition (ASC). Whilst recent years have seen the emergence of clinical and empirical reports delineating the profile of young autistic girls, recognition of sex differences in symptomatology in adulthood is far more limited.

Methods

We chose here to focus on symptomatology as reported using a screening instrument, the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R). In a meta-analysis, we pooled and analysed RAADS-R data from a number of experimental groups. Analysis of variance (ANOVA) searched for the presence of main effects of Sex and Diagnosis and for interactions between these factors in our sample of autistic and non-autistic adults.

Results

In social relatedness and circumscribed interests, main effects of Diagnosis revealed that as expected, autistic adults reported significantly greater lifetime prevalence of symptoms in these domains; an effect of Sex, in circumscribed interests, also suggested that males generally reported more prevalent symptoms than females. An interaction of Sex and Diagnosis in language symptomatology revealed that a normative sex difference in language difficulties was attenuated in autism. An interaction of Sex and Diagnosis in the sensorimotor domain revealed the opposite picture: a lack of sex differences between typically developing men and women and a greater prevalence of sensorimotor symptoms in autistic women than autistic men.

Conclusions

We discuss the literature on childhood sex differences in relation to those which emerged in our adult sample. Where childhood sex differences fail to persist in adulthood, several interpretations exist, and we discuss, for example, an inherent sampling bias that may mean that only autistic women most similar to the male presentation are diagnosed. The finding that sensorimotor symptomatology is more highly reported by autistic women is a finding requiring objective confirmation, given its potential importance in diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13229-018-0216-6) contains supplementary material, which is available to authorized users.

Bugs in the program: can pregnancy drugs and smoking disturb molecular reprogramming of the fetal germline, increasing heritable risk for autism and neurodevelopmental disorders?

In a seeming paradox, the prevalence of autism spectrum disorder (ASD) has surged, while at the same time research has pointed to the strong heritability of this neurodevelopmental pathology. Here an autism research philanthropist suggests a biological phenomenon of exogenously induced 'gamete disruption' that could reconcile these seemingly contradictory observations. Mining information from her own family history and that of her fellow autism parents, while also engaging with the scientific community, she proposes that a subset of the autisms may be rooted in a variety of molecular glitches in parental gametes induced by certain acute exposures during the parents' own fetal or neonatal development. These exposures include but are not limited to synthetic hormone drugs, tobacco, and general anesthesia. Consistent with this hypothesis, animal models have demonstrated adverse neurobehavioral outcomes in grandoffspring of gestating dams exposed to hormone-disrupting compounds, tobacco components, and general anesthesia. A recent epidemiological study showed a link between grandmaternal smoking and risk for ASD in grandoffspring through the maternal line. Given the urgency of the autism crisis, combined with the biological plausibility of this mostly unexplored paradigm, the writer contends that questions of nongenetic inheritance should be a priority in autism research.

Attention deficit hyperactivity disorder and autism spectrum disorder symptoms in school-age children born very preterm

BACKGROUND

Very preterm (VP) children face a broad range of neurodevelopmental sequelae, including behavioral problems.

AIM

To investigate prevalence, pervasiveness and co-occurrence of symptoms of attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in school-age children born very preterm.

METHODS

Using questionnaire and diagnostic interview data, parent and teacher reported symptoms of ADHD and ASD of 57 VP-children (mean age = 9.2 years) were compared with 57 gender and age matched full-term children using t-tests. Intra-class correlation coefficients quantified parent-teacher agreement. Correlation analysis investigated co-occurrence of ADHD/ASD symptoms. ADHD/ASD measures were aggregated using principal component analysis. Regression analyses investigated the contribution of perinatal risk factors, sex and SES to ADHD/ASD symptoms.

RESULTS

VP-children showed higher levels of parent and teacher reported attention problems, social impairment and compromised communication skills. Fair to strong agreement was found between parent and teacher reported ADHD and ASD symptoms, indicating pervasiveness of observed difficulties. Co-occurrence of ADHD and ASD symptoms in VP-children was found. Lower gestational age was associated with higher ADHD and ASD symptom levels, male sex with higher ADHD symptom levels and lower SES with higher ASD symptom levels.

CONCLUSION

School-age VP-children show higher levels of ADHD and ASD symptoms, and attention, socialization and communication difficulties in particular. Routinely screening for these problems is recommended in follow-up care.

Prenatal Maternal Serum Concentrations of Per- and Polyfluoroalkyl Substances in Association with Autism Spectrum Disorder and Intellectual Disability

BACKGROUND

Emerging work has examined neurodevelopmental outcomes following prenatal exposure to per- and polyfluoroalkyl substances (PFAS), but few studies have assessed associations with autism spectrum disorder (ASD).

OBJECTIVES

Our objective was to estimate associations of maternal prenatal PFAS concentrations with ASD and intellectual disability (ID) in children.

METHODS

Participants were from a population-based nested case-control study of children born from 2000 to 2003 in southern California, including children diagnosed with ASD (n=553), ID without autism (n=189), and general population (GP) controls (n=433). Concentrations of eight PFAS from stored maternal sera collected at 15-19 wk gestational age were quantified and compared among study groups. We used logistic regression to obtain adjusted odds ratios for the association between prenatal PFAS concentrations (parameterized continuously and as quartiles) and ASD versus GP controls, and separately for ID versus GP controls.

RESULTS

Geometric mean concentrations of most PFAS were lower in ASD and ID groups relative to GP controls. ASD was not significantly associated with prenatal concentrations of most PFAS, though significant inverse associations were found for perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) [adjusted ORs for the highest vs. lowest quartiles 0.62 (95% CI: 0.41, 0.93) and 0.64 (95% CI: 0.43, 0.97), respectively]. Results for ID were similar.

CONCLUSIONS

Results from this large case-control study with prospectively collected prenatal measurements do not support the hypothesis that prenatal exposure to PFAS is positively associated with ASD or ID. https://doi.org/10.1289/EHP1830.

The association between socioeconomic status and autism diagnosis in the United Kingdom for children aged 5–8 years of age: Findings from the Born in Bradford cohort

There has been recent interest in the relationship between socioeconomic status and the diagnosis of autism in children. Studies in the United States have found lower rates of autism diagnosis associated with lower socioeconomic status, while studies in other countries report no association, or the opposite. This article aims to contribute to the understanding of this relationship in the United Kingdom. Using data from the Born in Bradford cohort, comprising 13,857 children born between 2007 and 2011, it was found that children of mothers educated to A-level or above had twice the rate of autism diagnosis, 1.5% of children (95% confidence interval: 1.1%, 1.9%) compared to children of mothers with lower levels of education status 0.7% (95% confidence interval: 0.5%, 0.9%). No statistically significant relationship between income status or neighbourhood material deprivation was found after controlling for mothers education status. The results suggest a substantial level of underdiagnosis for children of lower education status mothers, though further research is required to determine the extent to which this is replicated across the United Kingdom. Tackling inequalities in autism diagnosis will require action, which could include increased education, awareness, further exploration of the usefulness of screening programmes and the provision of more accessible support services.

Factors Associated with Self-Injurious Behaviors in Children with Autism Spectrum Disorder: Findings from Two Large National Samples

In this study, we explored potential associations among self-injurious behaviors (SIB) and a diverse group of protective and risk factors in children with autism spectrum disorder from two databases: Autism and Developmental Disabilities Monitoring (ADDM) Network and the Autism Speaks-Autism Treatment Network (AS-ATN). The presence of SIB was determined from children's records in ADDM and a parent questionnaire in AS-ATN. We used multiple imputation to account for missing data and a non-linear mixed model with site as a random effect to test for associations. Despite differences between the two databases, similar associations were found; SIB were associated with developmental, behavioral, and somatic factors. Implications of these findings are discussed in relation to possible etiology, future longitudinal studies, and clinical practice.

Assisted reproductive technology has no association with autism spectrum disorders: The Taiwan Birth Cohort Study

The use of assisted reproduction technology has increased over the last two decades. Autism spectrum disorders and assisted reproduction technology share many risk factors. However, previous studies on the association between autism spectrum disorders and assisted reproduction technology have shown inconsistent results. The purpose of this study was to investigate the association between assisted reproduction technology and autism spectrum disorder diagnosis in a national birth cohort database. Furthermore, the results from the assisted reproduction technology and autism spectrum disorder propensity score matching exact matched datasets were compared. For this study, the 6- and 66-month Taiwan Birth Cohort Study datasets were used (N = 20,095). In all, 744 families were propensity score matching exact matched and selected as the assisted reproduction technology sample (ratio of assisted reproduction technology to controls: 1:2) and 415 families as the autism spectrum disorder sample (ratio of autism spectrum disorder to controls: 1:4). Using a national birth cohort dataset, controlling for the confounding factors of assisted reproduction technology conception and autism spectrum disorder diagnosis, both assisted reproduction technology and autism spectrum disorder propensity score matching matched datasets showed the same results of no association between assisted reproduction technology and autism spectrum disorder. Further study on the detailed information regarding the processes and methods of assisted reproduction technology may provide us with more information on the association between assisted reproduction technology and autism spectrum disorder.

Poverty and Trends in Three Common Chronic Disorders

OBJECTIVES

For asthma, attention-deficit/hyperactivity disorder (ADHD), and autism spectrum disorder (ASD), the objectives were to (1) describe the percent increases in prevalence and comorbidity and how these vary by poverty status, and (2) examine the extent to which poverty status is a predictor of higher than average comorbid conditions.

METHODS

Secondary analyses of the National Survey of Children's Health for years 2003, 2007, and 2011-2012 were conducted to identify trends in parent reported lifetime prevalence and comorbidity among children with asthma, ADHD, and ASD and examine variation by sociodemographic characteristics, poverty status, and insurance coverage. Using 2011-2012 data, multivariable regression was used to examine whether poverty status predicted higher than average comorbid conditions after adjusting for other sociodemographic characteristics.

RESULTS

Parent-reported lifetime prevalence of asthma and ADHD rose 18% and 44%, respectively, whereas the lifetime prevalence of ASD rose almost 400% (from 0.5% to 2%). For asthma, the rise was most prominent among the poor at 25.8%. For ADHD, the percent change by poverty status was similar (<100% federal poverty level [FPL]: 43.20%, 100% to 199% FPL: 52.38%, 200% to 399% FPL: 43.67%), although rise in ASD was associated with being nonpoor (200% to 399% FPL: 43.6%, ≥400% FPL: 36.0%). Publicly insured children with asthma, ADHD, and ASD also had significantly higher odds (1.9×, 1.6×, 3.0×, respectively) of having higher than average comorbidities.

CONCLUSIONS

Poverty status differentially influenced parent-reported lifetime prevalence and comorbidities of these target disorders. Future research is needed to examine parent and system-level characteristics that may further explain poverty's variable impact.

Perinatal Exposure to Traffic-Related Air Pollution and Autism Spectrum Disorders

BACKGROUND

Studies from the United States indicate that exposure to air pollution in early life is associated with autism spectrum disorders (ASD) in children, but the evidence is not consistent with European data.

OBJECTIVE

We aimed to investigate the association between exposure to air pollution from road traffic and the risk of ASD in children, with careful adjustment for socioeconomic and other confounders.

METHOD

Children born and residing in Stockholm, Sweden, during 1993-2007 with an ASD diagnosis were identified through multiple health registers and classified as cases (n = 5,136). A randomly selected sample of 18,237 children from the same study base constituted controls. Levels of nitrogen oxides (NOx) and particulate matter with diameter ≤ 10 μm (PM10) from road traffic were estimated at residential addresses during mother's pregnancy and the child's first year of life by dispersion models. Odds ratios (OR) and 95% confidence intervals (CI) for ASD with or without intellectual disability (ID) were estimated using logistic regression models after conditioning on municipality and calendar year of birth as well as adjustment for potential confounders.

RESULT

Air pollution exposure during the prenatal period was not associated with ASD overall (OR = 1.00; 95% CI: 0.86, 1.15 per 10-μg/m3 increase in PM10 and OR = 1.02; 95% CI: 0.94, 1.10 per 20-μg/m3 increase in NOx during mother's pregnancy). Similar results were seen for exposure during the first year of life, and for ASD in combination with ID. An inverse association between air pollution exposure and ASD risk was observed among children of mothers who moved to a new residence during pregnancy.

CONCLUSION

Early-life exposure to low levels of NOx and PM10 from road traffic does not appear to increase the risk of ASD. Citation: Gong T, Dalman C, Wicks S, Dal H, Magnusson C, Lundholm C, Almqvist C, Pershagen G. 2017. Perinatal exposure to traffic-related air pollution and autism spectrum disorders. Environ Health Perspect 125:119-126; http://dx.doi.org/10.1289/EHP118.

Feeding the microbiota-gut-brain axis: diet, microbiome, and neuropsychiatry

The microbial population residing within the human gut represents one of the most densely populated microbial niche in the human body with growing evidence showing it playing a key role in the regulation of behavior and brain function. The bidirectional communication between the gut microbiota and the brain, the microbiota-gut-brain axis, occurs through various pathways including the vagus nerve, the immune system, neuroendocrine pathways, and bacteria-derived metabolites. This axis has been shown to influence neurotransmission and the behavior that are often associated with neuropsychiatric conditions. Therefore, research targeting the modulation of this gut microbiota as a novel therapy for the treatment of various neuropsychiatric conditions is gaining interest. Numerous factors have been highlighted to influence gut microbiota composition, including genetics, health status, mode of birth, and environment. However, it is diet composition and nutritional status that has repeatedly been shown to be one of the most critical modifiable factors regulating the gut microbiota at different time points across the lifespan and under various health conditions. Thus the microbiota is poised to play a key role in nutritional interventions for maintaining brain health.

Prevalence and socioeconomic correlates of autism among children attending primary and secondary schools in south east Nigeria

OBJECTIVES

The objectives of the study were to determine the prevalence and socio-economic determinants of autism among children attending primary and secondary schools in South East, Nigeria.

METHODS

This was a cross-sectional study that assessed the prevalence and socio-economic pattern of childhood autism among children attending primary and secondary schools in Enugu and Ebonyi states, South East Nigeria. The questionnaire was adapted from American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR, 2000). The study was carried out between June and October, 2014. The schools were selected by listing all the mixed schools in the urban and semi- urban areas by simple random sampling.

RESULTS

A total of 721 subjects completed the questionnaire. The age of respondents ranged between 3 and 18 years, with mean age of 12.71 and standard deviation of 3.03 years. Twenty one children fulfilled the criteria for autism giving a prevalence of 2.9%. There is a significant association between age in categories (fishers exact test, p = 0.013) and social class (p=0.033).

CONCLUSION

The prevalence of autism was 2.9%; and the socio-economic characteristics of childhood autism in South East Nigeria are similar to those in other parts of the world.

Severity of ASD symptoms and their correlation with the presence of copy number variations and exposure to first trimester ultrasound

Current research suggests that incidence and heterogeneity of autism spectrum disorder (ASD) symptoms may arise through a variety of exogenous and/or endogenous factors. While subject to routine clinical practice and generally considered safe, there exists speculation, though no human data, that diagnostic ultrasound may also contribute to ASD severity, supported by experimental evidence that exposure to ultrasound early in gestation could perturb brain development and alter behavior. Here we explored a modified triple hit hypothesis [Williams & Casanova, ] to assay for a possible relationship between the severity of ASD symptoms and (1) ultrasound exposure (2) during the first trimester of pregnancy in fetuses with a (3) genetic predisposition to ASD. We did so using retrospective analysis of data from the SSC (Simon's Simplex Collection) autism genetic repository funded by the Simons Foundation Autism Research Initiative. We found that male children with ASD, copy number variations (CNVs), and exposure to first trimester ultrasound had significantly decreased non-verbal IQ and increased repetitive behaviors relative to male children with ASD, with CNVs, and no ultrasound. These data suggest that heterogeneity in ASD symptoms may result, at least in part, from exposure to diagnostic ultrasound during early prenatal development of children with specific genetic vulnerabilities. These results also add weight to on-going concerns expressed by the FDA about non-medical use of diagnostic ultrasound during pregnancy. Autism Res 2017, 10: 472-484. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

Autism spectrum disorder prevalence and associations with air concentrations of lead, mercury, and arsenic

Lead, mercury, and arsenic are neurotoxicants with known effects on neurodevelopment. Autism spectrum disorder (ASD) is a neurodevelopmental disorder apparent by early childhood. Using data on 4486 children with ASD residing in 2489 census tracts in five sites of the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring (ADDM) Network, we used multi-level negative binomial models to investigate if ambient lead, mercury, and arsenic concentrations, as measured by the US Environmental Protection Agency National-Scale Air Toxics Assessment (EPA-NATA), were associated with ASD prevalence. In unadjusted analyses, ambient metal concentrations were negatively associated with ASD prevalence. After adjusting for confounding factors, tracts with air concentrations of lead in the highest quartile had significantly higher ASD prevalence than tracts with lead concentrations in the lowest quartile (prevalence ratio (PR) = 1.36; 95 '% CI: 1.18, 1.57). In addition, tracts with mercury concentrations above the 75th percentile (>1.7 ng/m(3)) and arsenic concentrations below the 75th percentile (≤0.13 ng/m(3)) had a significantly higher ASD prevalence (adjusted RR = 1.20; 95 % CI: 1.03, 1.40) compared to tracts with arsenic, lead, and mercury concentrations below the 75th percentile. Our results suggest a possible association between ambient lead concentrations and ASD prevalence and demonstrate that exposure to multiple metals may have synergistic effects on ASD prevalence.

Autism As a Disorder of High Intelligence

A suite of recent studies has reported positive genetic correlations between autism risk and measures of mental ability. These findings indicate that alleles for autism overlap broadly with alleles for high intelligence, which appears paradoxical given that autism is characterized, overall, by below-average IQ. This paradox can be resolved under the hypothesis that autism etiology commonly involves enhanced, but imbalanced, components of intelligence. This hypothesis is supported by convergent evidence showing that autism and high IQ share a diverse set of convergent correlates, including large brain size, fast brain growth, increased sensory and visual-spatial abilities, enhanced synaptic functions, increased attentional focus, high socioeconomic status, more deliberative decision-making, profession and occupational interests in engineering and physical sciences, and high levels of positive assortative mating. These findings help to provide an evolutionary basis to understanding autism risk as underlain in part by dysregulation of intelligence, a core human-specific adaptation. In turn, integration of studies on intelligence with studies of autism should provide novel insights into the neurological and genetic causes of high mental abilities, with important implications for cognitive enhancement, artificial intelligence, the relationship of autism with schizophrenia, and the treatment of both autism and intellectual disability.

African American families on autism diagnosis and treatment: the influence of culture

Cultural factors such as health care access and autism spectrum disorder (ASD) symptom interpretations have been proposed as impacting delayed diagnosis and treatment for African American children with ASD. A qualitative study of urban African American families caring for their child with autism was conducted with 24 family members and 28 ASD professionals. Cultural caring meant families protected their child from harm including potential or actual distrustful encounters, and took action for their child and community to optimize their child's health and address the knowledge deficits of ASD within their community. Families and professionals believed cultural influences delayed families' receiving and seeking appropriate health care for the African American child with ASD affecting timely autism diagnosis and treatment.

Socioeconomic status and intelligence quotient as predictors of psychiatric disorders in children and adolescents with high-functioning autism spectrum disorder and in their siblings

Previous studies have shown high rates of comorbid disorders in children and adolescents with autism spectrum disorder, but failed to compare them with general population and few of them have identified predictors of comorbidity. This study compared the rates of psychiatric disorders in 50 children and adolescents with autism spectrum disorder, 24 of their siblings, 32 controls from general population and 22 of their siblings. Children and adolescent with autism spectrum disorder and their siblings had higher rates of attention deficit and hyperactivity disorder compared to controls. Lower socioeconomic status and intelligence quotient were the main risk factors. The contribution of socioeconomic status and intelligence quotient to increase the risk of developing comorbidity in autism spectrum disorder and psychopathology in their siblings deserves further study.

Age at diagnosis of autism spectrum disorders: is there an association with socioeconomic status and family self-education about autism?

BACKGROUND

The marked increase in autism spectrum disorders (ASD) prevalence has stimulated worldwide interest in exploring broader circumstances of care of autistic children, including the role of socioeconomic status (SES) and family information on autism.

METHODS

Our sample comprised of 160 children who participated in a diagnostic examination focused on autism, and their parents who completed a simple descriptive questionnaire focusing on the family situation as well as family self-education about autism. The diagnosis of ASD was confirmed in 120 children (75% of the sample; 94 boys, 26 girls) with mean age 6.2±2.7 years (median 5.3, range 2.2-17.2 years). In 71 autistic patients (59.2%), a diagnosis of mental retardation was also established.

RESULTS

The age at diagnosis of ASD correlated negatively with maternal (P=0.014) and paternal (P=0.002) ages at the time of birth of the ASD child as well as with paternal (P=0.002) and maternal (P=0.050) education. The age at diagnosis of ASD did not correlate with family SES. Mothers were significantly more active in seeking information on autism than fathers or both parents equally (80 vs 9 vs 28 cases, respectively; P<0.001). The mean number of information sources on autism was 3.5±1.8 with a range 0-9. The mean number of resources did not differ among the three SES groups (3.50 vs 3.49 vs 4.25, respectively; P=0.704). The mean number of sources did not correlate with the age at diagnosis of ASD. The most often used sources were the Internet (81.7%), followed by psychologists (48.3%), books (46.7%), and child and adolescent psychiatrists (43.3%).

CONCLUSION

An earlier diagnosis of ASD is associated with higher parental age at birth and higher parental education but not with family SES or number of family information sources.

Socioeconomic Disparities and Prevalence of Autism Spectrum Disorders and Intellectual Disability

Background and Objectives

Study of the impact of socioeconomic status on autism spectrum disorders (ASD) and severe intellectual disabilities (ID) has yielded conflicting results. Recent European studies suggested that, unlike reports from the United States, low socioeconomic status is associated with an increased risk of ASD. For intellectual disabilities, the links with socioeconomic status vary according to the severity. We wished to clarify the links between socioeconomic status and the prevalence of ASD (with or without ID) and isolated severe ID.

Methods

500 children with ASD and 245 children with severe ID (IQ <50) aged 8 years, born 1995 to 2004, were recruited from a French population-based registry. Inclusions were based on clinical diagnoses reported in medical records according to the International Classification of Diseases, 10^th Revision. Socioeconomic status was measured by indicators available at block census level which characterize the population of the child’s area of residence. Measures of deprivation, employment, occupation, education, immigration and family structure were used. Prevalences were compared between groups of census units defined by the tertiles of socioeconomic level in the general population.

Results

Prevalence of ASD with associated ID was higher in areas with the highest level of deprivation and the highest percentage of unemployed adults, persons with no diploma, immigrants and single-parent families. No association was found when using occupational class. Regarding ASD without associated ID, a higher prevalence was found in areas with the highest percentage of immigrants. No association was found for other socioeconomic indicators. The prevalence of isolated severe ID was likely to be higher in the most disadvantaged groups defined by all indicators.

Conclusion

The prevalence of ASD with associated ID and of severe isolated ID is more likely to be higher in areas with the highest level of deprivation.