The epidemiology of autism spectrum disorders

Autism spectrum disorder detection using facial images: A performance comparison of pretrained convolutional neural networks

Autism spectrum disorder (ASD) is a complex psychological syndrome characterized by persistent difficulties in social interaction, restricted behaviours, speech, and nonverbal communication. The impacts of this disorder and the severity of symptoms vary from person to person. In most cases, symptoms of ASD appear at the age of 2 to 5 and continue throughout adolescence and into adulthood. While this disorder cannot be cured completely, studies have shown that early detection of this syndrome can assist in maintaining the behavioural and psychological development of children. Experts are currently studying various machine learning methods, particularly convolutional neural networks, to expedite the screening process. Convolutional neural networks are considered promising frameworks for the diagnosis of ASD. This study employs different pre-trained convolutional neural networks such as ResNet34, ResNet50, AlexNet, MobileNetV2, VGG16, and VGG19 to diagnose ASD and compared their performance. Transfer learning was applied to every model included in the study to achieve higher results than the initial models. The proposed ResNet50 model achieved the highest accuracy, 92%, compared to other transfer learning models. The proposed method also outperformed the state-of-the-art models in terms of accuracy and computational cost.

The emerging role of extracellular vesicles in the diagnosis and treatment of autism spectrum disorders

Autism spectrum disorders (ASD) are neurodevelopmental conditions characterized by restricted, repetitive behavioral patterns and deficits in social interactions. The prevalence of ASD has continued to rise in recent years. However, the etiology and pathophysiology of ASD remain largely unknown. Currently, the diagnosis of ASD relies on behavior measures, and there is a lack of reliable and objective biomarkers. In addition, there are still no effective pharmacologic therapies for the core symptoms of ASD. Extracellular vesicles (EVs) are lipid bilayer nanovesicles secreted by almost all types of cells. EVs play a vital role in cell-cell communications and are known to bear various biological functions. Emerging evidence demonstrated that EVs are involved in many physiological and pathological processes throughout the body and the content in EVs can reflect the status of the originating cells. EVs have demonstrated the potential of broad applications for the diagnosis and treatment of various brain diseases, suggesting that EVs may have also played a role in the pathological process of ASD. Besides, EVs can be utilized as therapeutic agents for their endogenous substances and biological functions. Additionally, EVs can serve as drug delivery tools as nano-sized vesicles with inherent targeting ability. Here, we discuss the potential of EVs to be considered as promising diagnostic biomarkers and their potential therapeutic applications for ASD.

Characterizing Genetic Pathways Unique to Autism Spectrum Disorder at Multiple Levels of Biological Analysis

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by atypical patterns of social functioning and repetitive/restricted behaviors. ASD commonly co-occurs with ADHD and, despite their clinical distinctiveness, the two share considerable genetic overlap. Given their shared genetic liability, it is unclear which genetic pathways confer unique risk for ASD independent of ADHD. We applied Genomic Structural Equation Modeling (SEM) to GWAS summary statistics for ASD and ADHD, decomposing the genetic signal for ASD into that which is unique to ASD (uASD) and that which is shared with ADHD. We computed genetic correlations between uASD and 75 external traits to estimate genetic overlap between uASD and other clinically relevant phenotypes. We went on to apply Stratified Genomic SEM to identify classes of genes enriched for uASD. Finally, we implemented Transcriptome-Wide SEM (T-SEM) to explore patterns of gene-expression associated with uASD. We observed positive genetic correlations between uASD and several external traits, most notably those relating to cognitive/educational outcomes and internalizing psychiatric traits. Stratified Genomic SEM showed that heritability for uASD was significantly enriched in genes involved in evolutionarily conserved processes, as well as for a histone mark in the germinal matrix. T-SEM revealed 83 unique genes with expression associated with uASD, many of which were novel. These findings delineate the unique biological underpinnings of ASD which exist independent of ADHD and demonstrate the utility of Genomic SEM and its extensions for disambiguating shared and unique risk pathways for genetically overlapping traits.

Prevalence of autism spectrum disorder in mainland china over the past 6 years: a systematic review and meta-analysis

BACKGROUND

Coupled with its rising prevalence, Autism spectrum disorder (ASD) has become a globally recognized public health concern. Nevertheless, large-scale, multicenter studies that analyze the epidemiology of ASD in China are relatively scarce.

METHODS

Literature searches were conducted in PubMed/Medline, Embase, the Cochrane Library, Wanfang Data Knowledge Service Platform, China Biology Medicine database (CBM), China Science and Technology Journal Database (CSTJ), and China National Knowledge Infrastructure (CNKI) to retrieve studies published before April 8, 2023, related to ASD prevalence among children aged 0 to 14 years in mainland China. Meta-analysis was conducted using RevMan 5.2 and Stata 14.0.

RESULTS

Twenty-one articles were included. The ASD prevalence among children in mainland China has been 0.7% (95% confidence interval(CI): 0.006-0.008) since 2017. The prevalence of ASD among boys was 1.0% (95% CI: 0.008-0.011), which was significantly higher than that among girls at 0.2% (95% CI: 0.002-0.003), with a statistically significant difference (OR = 3.198, 95% CI: 2.489-4.109, P = 0.000). Among the included studies, 18 reported an ASD prevalence of 0.8% (95% CI: 0.007-0.010), while 3 studies reported an autistic disorder (AD) prevalence of 0.7% (95% CI: 0.006-0.008). The prevalence of autism among urban children was 23.9% (95% CI: 0.149-0.328), and in rural areas, it was 0.7% (95% CI: 0.002-0.013), with no statistically significant difference (OR = 1.342, 95% CI: 0.258-6.975, P = 0.727). Regression analysis showed that factors such as region (P = 0.000), age (P = 0.000), study period (P = 0.000), sample size (P = 0.000), sampling method (P = 0.002), population source (P = 0.000), disease type (P = 0.000), quality score of the study (P = 0.000), and diagnostic criteria (P = 0.000) might have contributed to the heterogeneity in ASD prevalence.

CONCLUSION

The prevalence of ASD in China from 2017 to 2023 was 7/1000, showing an upward trend compared to that before 2017 (26.50/10,000). The male-to-female prevalence ratio was 5:1.The overall prevalence remained significantly lower than that reported in foreign countries.

A snapshot on introspection of autism spectrum disorder

Autism spectrum disorder is a neurodevelopmental condition marked by restricted interests and difficulty with social communication. ASD is characterized by heightened neuroinflammation and irregular neuronal connections. ASD is more frequent in male than female with male-female ratio of around 4:1. ASD affects 2.8% or 1 in 36 8-year-olds, based on the CDC's Morbidity and Mortality Weekly Report. Various factors like Environmental, Genetic, Epigenetic and Developmental factors are linked with genesis of ASD. Repetitive behaviors, Impaired communication skills, difficulty with social interaction are some of the clinical features of ASD. Current Pharmacotherapy of ASD limits to management of symptoms only, not cure. The stem cell therapy has a promising potential to be a breakthrough in treating ASD. Various types of stem cells have been successfully tested in children with ASD. AI has a potential to emerge as a tool for early detection of ASD. Robotics can assist the children with ASD to overcome the challenges associated with ASD.

Gestational thyroid hormones and autism-related traits in the EARLI and HOME studies

Thyroid hormones are essential for neurodevelopment. Few studies have considered associations with quantitatively measured autism spectrum disorder (ASD)-related traits, which may help elucidate associations for a broader population. Participants were drawn from two prospective pregnancy cohorts: the Early Autism Risk Longitudinal Investigation (EARLI), enrolling pregnant women who already had a child with ASD, and the Health Outcomes and Measures of the Environment (HOME) Study, following pregnant women from the greater Cincinnati, OH area. Gestational thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured in mid-pregnancy 16 (±3) weeks gestation serum samples. ASD-related traits were measured using the Social Responsiveness Scale (SRS) at ages 3-8 years. The association was examined using quantile regression, adjusting for maternal and sociodemographic factors. 278 participants (132 from EARLI, 146 from HOME) were included. TSH distributions were similar across cohorts, while FT4 levels were higher in EARLI compared to HOME. In pooled analyses, particularly for those in the highest SRS quantile (95th percentile), higher FT4 levels were associated with increasing SRS scores (β = 5.21, 95% CI = 0.93, 9.48), and higher TSH levels were associated with decreasing SRS scores (β = -6.94, 95% CI = -11.04, -2.83). The association between TSH and SRS remained significant in HOME for the 95% percentile of SRS scores (β = -6.48, 95% CI = -12.16, -0.80), but not EARLI. Results for FT4 were attenuated when examined in the individual cohorts. Our results add to evidence that gestational thyroid hormones may be associated with ASD-related outcomes by suggesting that relationships may differ across the distribution of ASD-related traits and by familial likelihood of ASD.

Neuroimmune mechanisms in autism etiology - untangling a complex problem using human cellular models

Autism spectrum disorder (ASD) affects 1 in 36 people and is more often diagnosed in males than in females. Core features of ASD are impaired social interactions, repetitive behaviors and deficits in verbal communication. ASD is a highly heterogeneous and heritable disorder, yet its underlying genetic causes account only for up to 80% of the cases. Hence, a subset of ASD cases could be influenced by environmental risk factors. Maternal immune activation (MIA) is a response to inflammation during pregnancy, which can lead to increased inflammatory signals to the fetus. Inflammatory signals can cross the placenta and blood brain barriers affecting fetal brain development. Epidemiological and animal studies suggest that MIA could contribute to ASD etiology. However, human mechanistic studies have been hindered by a lack of experimental systems that could replicate the impact of MIA during fetal development. Therefore, mechanisms altered by inflammation during human pre-natal brain development, and that could underlie ASD pathogenesis have been largely understudied. The advent of human cellular models with induced pluripotent stem cell (iPSC) and organoid technology is closing this gap in knowledge by providing both access to molecular manipulations and culturing capability of tissue that would be otherwise inaccessible. We present an overview of multiple levels of evidence from clinical, epidemiological, and cellular studies that provide a potential link between higher ASD risk and inflammation. More importantly, we discuss how stem cell-derived models may constitute an ideal experimental system to mechanistically interrogate the effect of inflammation during the early stages of brain development.

Puerarin attenuates valproate-induced features of ASD in male mice via regulating Slc7a11-dependent ferroptosis

Autism spectrum disorder (ASD) is a complicated, neurodevelopmental disorder characterized by social deficits and stereotyped behaviors. Accumulating evidence suggests that ferroptosis is involved in the development of ASD, but the underlying mechanism remains elusive. Puerarin has an anti-ferroptosis function. Here, we found that the administration of puerarin from P12 to P15 ameliorated the autism-associated behaviors in the VPA-exposed male mouse model of autism by inhibiting ferroptosis in neural stem cells of the hippocampus. We highlight the role of ferroptosis in the hippocampus neurogenesis and confirm that puerarin treatment inhibited iron overload, lipid peroxidation accumulation, and mitochondrial dysfunction, as well as enhanced the expression of ferroptosis inhibitory proteins, including Nrf2, GPX4, Slc7a11, and FTH1 in the hippocampus of VPA mouse model of autism. In addition, we confirmed that inhibition of xCT/Slc7a11-mediated ferroptosis occurring in the hippocampus is closely related to puerarin-exerted therapeutic effects. In conclusion, our study suggests that puerarin targets core symptoms and hippocampal neurogenesis reduction through ferroptosis inhibition, which might be a potential drug for autism intervention.

Environmental Risk Factors in Autism Spectrum Disorder: A Narrative Review

Existing evidence indicates that environmental factors might contribute up to 50% of the variance in autism spectrum disorder (ASD) risk. This structured narrative review offers a comprehensive synthesis of current knowledge on environmental risk factors in ASD, including evaluation of conflicting evidence, exploration of underlying mechanisms, and suggestions for future research directions. Analysis of diverse epidemiological investigations indicates that certain environmental factors, including advanced parental age, preterm birth, delivery complications, and exposure to toxic metals, drugs, air pollutants, and endocrine-disrupting chemicals, are linked to an increased ASD risk through various mechanisms such as oxidative stress, inflammation, hypoxia, and its consequences, changes in neurotransmitters, disruption of signaling pathways and some others. On the other hand, pregnancy-related factors such as maternal diabetes, maternal obesity, and caesarian section show a weaker association with ASD risk. At the same time, other environmental factors, such as vaccination, maternal smoking, or alcohol consumption, are not linked to the risk of ASD. Regarding nutritional elements data are inconclusive. These findings highlight the significance of environmental factors in ASD etiology and emphasize that more focused research is needed to target the risk factors of ASD. Environmental interventions targeting modifiable risk factors might offer promising avenues for ASD prevention and treatment.

Probiotics, prebiotics, and synbiotics for patients with autism spectrum disorder: a meta-analysis and umbrella review

Background and objective

The potential impact of gut health on general physical and mental well-being, particularly in relation to brain function, has led to a growing interest in the potential health advantages of prebiotics, probiotics, and synbiotics for the management of ASD. A comprehensive meta-analysis and systematic review was conducted in order to evaluate the effectiveness and protection of many drugs targeted at manipulating the microbiota in the treatment of ASD.

Methods

The present study employed a comprehensive examination of various electronic databases yielded a total of 3,393 records that were deemed possibly pertinent to the study. RCTs encompassed a total of 720 individuals between the ages of 2 and 17, as well as 112 adults and participants ranging from 5 to 55 years old, all of whom had received a diagnosis of ASD.

Results

Overall, 10 studies reported Autism-Related Behavioral Symptoms (ARBS). Regarding the enhancement of autism-related behavioral symptoms, there wasn't a statistically significant difference between the intervention groups (combined standardized mean difference = -0.07, 95% confidence interval: -0.39 to 0.24, Z = 0.46, p = 0.65). We observed that in the patients with ASD treated with probiotic frontopolar's power decreased significantly from baseline to endpoints in beta band (Baseline: 13.09 ± 3.46, vs. endpoint: 10.75 ± 2.42, p = 0.043, respectively) and gamma band (Baseline: 5.80 ± 2.42, vs. endpoint: 4.63 ± 1.39, p = 0.033, respectively). Among all tested biochemical measures, a significant negative correlation was found between frontopolar coherence in the gamma band and TNF-α (r = -0.30, p = 0.04).

Conclusion

The existing body of research provides a comprehensive analysis of the developing evidence that indicates the potential of probiotics, prebiotics, and synbiotics as therapeutic therapies for ASD. Our findings revealed that those there was no significant effect of such therapy on autism-related behavioral symptoms, it has significant effect on the brain connectivity through frontopolar power in beta and gamma bands mediated by chemicals and cytokines, such as TNF-α. The psychobiotics showed no serious side-effects.

Environmental Influences on Individuals with Autistic Spectrum Disorders with Special Emphasis on Seasonality: An Overview

This paper offers an in-depth exploration of the intricate relationship between environmental factors and autism spectrum disorder (ASD), with a special emphasis on seasonality. It reviews existing research, providing a comprehensive summary of findings and highlighting the multifaceted dimensions of several environmental factors influencing the etiology of ASD. The discussion encompasses various elements, including birth months, maternal health, dietary choices, and vitamin D deficiency, delving into the intricate interplay of seasonality with environmental influences such as viral infections and solar radiation. The present study raises essential questions regarding the timing of environmental influences and the factors contributing to the rising prevalence of ASD. Ultimately, it underscores the need for future epidemiological research to incorporate more extensive investigations of environmental risk factors and employ advanced statistical analyses. This comprehensive overview contributes to a deeper understanding of how environmental factors, particularly seasonality, may be linked to the occurrence of ASD and its increasing prevalence, recognizing the multifaceted and diverse nature of these interactions.

Iron metabolism in autism spectrum disorder; inference through single nucleotide polymorphisms in key iron metabolism genes

Autism spectrum disorder (ASD) is a heterogeneous group of neurodevelopmental problems with various genetic and environmental components. The ASD diagnosis is based on symptom expression without reliance on any biomarkers. The genetic contributions in ASD remain elusive. Various studies have linked ASD with iron. Since iron plays a crucial role in brain development, neurotransmitter synthesis, neuronal myelination and mitochondrial function, we hypothesized that iron dysregulation in the brain could play a role and contribute to the pathogenesis of ASD. In this study, we investigated single nucleotide polymorphisms in ASD in various iron metabolism genes, including the Transferrin Receptor (TFRC) gene (rs11915082), the Solute Carrier Family 11 Member 2 (SLC11A2) gene (rs1048230 and rs224589), the Solute Carrier Family 40 Member 1 (SLC40A1) gene (rs1439816), and hepcidin antimicrobial peptide (HAMP) gene (rs10421768). We recruited 48 patients with ASD and 88 matched non-ASD controls. Our results revealed a significant difference between ASD and controls in the G allele of the TFRC gene rs11915082, and in the C allele of the SLC40A1 gene rs1439816. In silico analysis demonstrated potential positive role of the indicated genetic variations in ASD development and pathogenesis. These results suggest that specific genetic variations in iron metabolism genes may represent part of early genetic markers for early diagnosis of ASD. A significant effect of SNPs, groups (ASD/control) as well as interaction between SNPs and groups was revealed. Follow-up post hoc tests showed a significant difference between the ASD and control groups in rs11915082 (TFRC gene) and rs1439816 (SLC40A1 gene). Backward conditional logistic regression using both the genotype and allele data showed similar ability in detecting ASD using allel model (Nagelkerke R2 = 0.350 p = 0.967; Variables: rs1439816, rs11915082) compared to genotype model (Nagelkerke R2 = 0.347, p = 0.430; Variables: rs1439816 G, rs1439816 C, rs10421768 A). ROC curve showed 54% sensitivity in detecting ASD compared to 47% for the genotype model. Both models differentiated controls with high accuracy; the allele model had a specificity of 91% compared to 92% for the genotype model. In conclusion, our findings suggest that specific genetic variations in iron metabolism may represent early biomarkers for a diagnosis of ASD. Further research is needed to correlate these markers with specific blood iron indicators and their contribution to brain development and behavior.

Screening for Autism Spectrum Condition Through Inner City Homeless Services in the Republic of Ireland

Homeless service users were screened for autism spectrum disorder through one of Ireland's leading not for profit service providers. Keyworkers acted as proxy informants; their caseloads were screened using the DSM-5-Autistic Traits in the Homeless Interview (DATHI). Client current and historical health and behaviour data was collated. A representative sample of 106 eligible keyworkers caseloads were screened, identifying 3% "present" and 9% "possibly present" for autistic traits with the DATHI. These findings suggest a high estimate of autism prevalence and support emerging evidence that, people with autism are overrepresented in the homeless population, compared to housed populations. Autism may be a risk factor for entry into homelessness and a challenge to exiting homeless and engaging with relevant services.

Comparative yield of molecular diagnostic algorithms for autism spectrum disorder diagnosis in India: evidence supporting whole exome sequencing as first tier test

BACKGROUND

Autism spectrum disorder (ASD) affects 1 in 100 children globally with a rapidly increasing prevalence. To the best of our knowledge, no data exists on the genetic architecture of ASD in India. This study aimed to identify the genetic architecture of ASD in India and to assess the use of whole exome sequencing (WES) as a first-tier test instead of chromosomal microarray (CMA) for genetic diagnosis.

METHODS

Between 2020 and 2022, 101 patient-parent trios of Indian origin diagnosed with ASD according to the Diagnostic and Statistical Manual, 5th edition, were recruited. All probands underwent a sequential genetic testing pathway consisting of karyotyping, Fragile-X testing (in male probands only), CMA and WES. Candidate variant validation and parental segregation analysis was performed using orthogonal methods.

RESULTS

Of 101 trios, no probands were identified with a gross chromosomal anomaly or Fragile-X. Three (2.9%) and 30 (29.7%) trios received a confirmed genetic diagnosis from CMA and WES, respectively. Amongst diagnosis from WES, SNVs were detected in 27 cases (90%) and CNVs in 3 cases (10%), including the 3 CNVs detected from CMA. Segregation analysis showed 66.6% (n = 3 for CNVs and n = 17 for SNVs) and 16.6% (n = 5) of the cases had de novo and recessive variants respectively, which is in concordance with the distribution of variant types and mode of inheritance observed in ASD patients of non-Hispanic white/ European ethnicity. MECP2 gene was the most recurrently mutated gene (n = 6; 20%) in the present cohort. Majority of the affected genes identified in the study cohort are involved in synaptic formation, transcription and its regulation, ubiquitination and chromatin remodeling.

CONCLUSIONS

Our study suggests de novo variants as a major cause of ASD in the Indian population, with Rett syndrome as the most commonly detected disorder. Furthermore, we provide evidence of a significant difference in the diagnostic yield between CMA (3%) and WES (30%) which supports the implementation of WES as a first-tier test for genetic diagnosis of ASD in India.

Comorbidity and Overlaps between Autism Spectrum and Borderline Personality Disorder: State of the Art

Despite the relationship between Autism spectrum disorder (ASD) and personality disorders (PD) still being scarcely understood, recent investigations increased awareness about significant overlaps between some PD and autism spectrum conditions. In this framework, several studies suggested the presence of similarities between BPD and ASD symptoms and traits, based on the recent literature that increasingly reported increased comorbidity rates and significant symptomatologic overlaps between the two conditions. The aim of this review is to describe the available studies about the prevalence of the association between different forms of autism spectrum (full-fledged clinical conditions as well as subthreshold autistic traits) and BPD. Despite some controversial results and lack of homogeneity in the methods used for the diagnostic assessment, the reviewed literature highlighted how subjects with BPD reported higher scores on tests evaluating the presence of AT compared to a non-clinical population and hypothesized the presence of unrecognized ASD in some BPD patients or vice versa, while also describing a shared vulnerability towards traumatic events, and a greater risk of suicidality in BPD subjects with high autistic traits. However, the specific measure and nature of this association remain to be explored in more depth.

Heterogeneity of Autism Characteristics in Genetic Syndromes: Key Considerations for Assessment and Support

Purpose of Review

Elevated prevalence of autism characteristics is reported in genetic syndromes associated with intellectual disability. This review summarises recent evidence on the behavioural heterogeneity of autism in the following syndromes: Fragile X, Cornelia de Lange, Williams, Prader-Willi, Angelman, Down, Smith-Magenis, and tuberous sclerosis complex. Key considerations for assessment and support are discussed.

Recent Findings

The profile and developmental trajectory of autism-related behaviour in these syndromes indicate some degree of syndrome specificity which may interact with broader behavioural phenotypes (e.g. hypersociability), intellectual disability, and mental health (e.g. anxiety). Genetic subtype and co-occurring epilepsy within syndromes contribute to increased significance of autism characteristics. Autism-related strengths and challenges are likely to be overlooked or misunderstood using existing screening/diagnostic tools and criteria, which lack sensitivity and specificity within these populations.

Summary

Autism characteristics are highly heterogeneous across genetic syndromes and often distinguishable from non-syndromic autism. Autism diagnostic assessment practices in this population should be tailored to specific syndromes. Service provisions must begin to prioritise needs-led support.

Autism spectrum disorder research: knowledge mapping of progress and focus between 2011 and 2022

Background

In recent years, a large number of studies have focused on autism spectrum disorder (ASD). The present study used bibliometric analysis to describe the state of ASD research over the past decade and identify its trends and research fronts.

Methods

Studies on ASD published from 2011 to 2022 were obtained from the Web of Science Core Collection (WoSCC). Bibliometrix, CiteSpace, and VOSviewer were used for bibliometric analysis.

Results

A total of 57,108 studies were included in the systematic search, and articles were published in more than 6,000 journals. The number of publications increased by 181.7% (2,623 in 2011 and 7,390 in 2021). The articles in the field of genetics are widely cited in immunology, clinical research, and psychological research. Keywords co-occurrence analysis revealed that "causative mechanisms," "clinical features," and "intervention features" were the three main clusters of ASD research. Over the past decade, genetic variants associated with ASD have gained increasing attention, and immune dysbiosis and gut microbiota are the new development frontiers after 2015.

Conclusion

This study uses a bibliometric approach to visualize and quantitatively describe autism research over the last decade. Neuroscience, genetics, brain imaging studies, and gut microbiome studies improve our understanding of autism. In addition, the microbe-gut-brain axis may be an exciting research direction for ASD in the future. Therefore, through visual analysis of autism literature, this paper shows the development process, research hotspots, and cutting-edge trends in this field to provide theoretical reference for the development of autism in the future.

Epidemiological Study of Autism Spectrum Disorders in Greece for 2021: Nationwide Prevalence in 2–17-Year-Old Children and Regional Disparities

This study estimated the crude prevalence of autism spectrum disorders (ASD) in Greece in 2021. A retrospective study was conducted for 2021 using data provided for research purposes for the first time by the Greek National Health Service Organization for Healthcare Services Provision (EOPYY) related to the ICD-10 diagnosis codes F84.0–F84.9 (ASD). Treatments were categorized by gender, age, and location. Statistical analysis was performed using the open-source software R. In total, 15,706 children aged 2–17 years were registered with ASD: 12,380 boys and 3326 girls. In total, 6,117,910 therapies were prescribed: 4,844,173 for boys and 1,273,737 for girls. Boys are estimated to be diagnosed 3.5 times more often than girls. On average, approximately 390 treatments are prescribed per person per year for both sexes. The annual prevalence is estimated at 0.94%, ranging from 0.42% to 1.44% depending on geographic region. Our findings provide evidence-based data for the planning of policies regarding health, education, and employment for people with ASD. The number of children and treatments makes ASD a public health concern to support children and their families and ensure equal participation in all aspects of society.

Effects of Probiotics on Autism Spectrum Disorder in Children: A Systematic Review and Meta-Analysis of Clinical Trials

Many studies have explored the efficacy of probiotics on autism spectrum disorder (ASD) in children, but there is no consensus on the curative effect. This systematic review and meta-analysis aimed to comprehensively investigate whether probiotics could improve behavioral symptoms in children with ASD. A systematic database search was conducted and a total of seven studies were included in the meta-analysis. We found a nonsignificant overall effect size of probiotics on behavioral symptoms in children with ASD (SMD = −0.24, 95% CI: −0.60 to 0.11, p = 0.18). However, a significant overall effect size was found in the subgroup of the probiotic blend (SMD = −0.42, 95% CI: −0.83 to −0.02, p = 0.04). Additionally, these studies provided limited evidence for the efficacy of probiotics due to their small sample sizes, a shorter intervention duration, different probiotics used, different scales used, and poor research quality. Thus, randomized, double-blind, and placebo-controlled studies following strict trial guidelines are needed to precisely demonstrate the therapeutic effects of probiotics on ASD in children.

Measuring Social Camouflaging in Individuals with High Functioning Autism: A Literature Review

In the recent years, growing attention has been paid to the use of camouflaging strategies by adult populations suffering from autism spectrum disorder (ASD) with milder manifestations and without intellectual impairment, which may lead to a delay in diagnosis or even a misdiagnosis. In fact, high-functioning ASD individuals were reported to be more aware of their communication difficulties and were more likely make considerable efforts to adjust their behavior to conventional rules of non-autistic individuals, learning to imitate other non-ASD individuals. Moreover, females reported a higher frequency of camouflaging strategies, suggesting a role of camouflaging in the gender gap of the ASD diagnosis. Although camouflaging strategies can sometimes grant a better level of adjustment, even resulting in a hyper-adaptive behavior, they are also often correlated with negative mental health consequences due to the long-term stress associated with continuous attempts to adapt in day-to-day life. In this framework, the aim of the present work was to review the available studies that assessed the presence and correlates of camouflaging strategies in individuals with ASD. Although the literature available on the topic is still scarce, some interesting correlations between camouflaging and anxious and depressive symptoms, as well as suicidality, were highlighted. In particular, the controversial and sometime opposite thoughts and results about camouflaging may be clarified and integrated in light of a dimensional approach to psychopathology.

Relationship of Nonsteroidal Anti-Inflammatory Drug Use During Pregnancy with Autism Spectrum Disorder and Intellectual Disability Among Offspring

Objective: This study aimed to examine the association of nonsteroidal anti-inflammatory drug (NSAID) use by pregnant women during pregnancy with autism spectrum disorder (ASD) and intellectual disability (ID) in their children among Medicaid-insured mother-child dyads. Materials and Methods: We conducted a retrospective cohort study linking multiple datasets of South Carolina for the years between 2010 and 2017, in which the main exposure variable was NSAID use during pregnancy and outcome variables were ASD only, ID only, and ASD with ID. We conducted a multinomial logistic regression analysis, controlling for identified risk factors for ASD (mother's age, race, body-mass index, preeclampsia, and gestational diabetes). Results: NSAID use during pregnancy was found to be associated with ID only in both unadjusted and adjusted analyses. Children with mothers who had NSAID prescriptions were 26% more likely to have ID in comparison with children whose mothers did not have NSAID prescriptions (odds ratio: 1.26 [1.10-1.46]). The other risk factors identified for ASD were maternal age, race, preeclampsia, smoking, low birth weight, and obesity. For ID, the risk factors were maternal age, race, smoking, birth weight, overweight, and obesity, all of which were also associated with ASD with ID, except for overweight. Conclusions: NSAID usage during pregnancy was found to be associated with ID only and not with ASD. However, more research is needed to validate the effect of NSAIDs during pregnancy on ASD and ID among children.

Prevalence and Disparities in the Detection of Autism Without Intellectual Disability

BACKGROUND

Intellectual ability predicts functional outcomes for children with autism spectrum disorder (ASD). It is essential to classify ASD children with and without intellectual disability (ID) to aid etiological research, provide services, and inform evidence-based educational and health planning.

METHODS

Using a cross-sectional study design, data from 2000 to 2016 active ASD surveillance among 8-year-olds residing in the New York-New Jersey Metropolitan Area were analyzed to determine ASD prevalence with and without ID. Multivariable Poisson regression models were used to identify trends for ASD with ID (ASD-I) and without ID (ASD-N).

RESULTS

Overall, 4661 8-year-olds were identified with ASD. Those that were ASI-I were 1505 (32.3%) and 2764 (59.3%) were ASD-N. Males were 3794 (81.4%), 946 (20.3%) were non-Hispanic Black (Black), 1230 (26.4%) were Hispanic, and 2114 (45.4%) were non-Hispanic white (white). We observed 2-fold and 5-fold increases in the prevalence of ASD-I and ASD-N, respectively, from 2000-2016. Black children were 30% less likely to be identified with ASD-N compared with white children. Children residing in affluent areas were 80% more likely to be identified with ASD-N compared with children in underserved areas. A greater proportion of children with ASD-I resided in vulnerable areas compared with children with ASD-N. Males had higher prevalence compared with females regardless of ID status; however, male-to-female ratios were slightly lower among ASD-I compared with ASD-N cases.

CONCLUSIONS

One-in-3 children with ASD had ID. Disparities in the identification of ASD without ID were observed among Black and Hispanic children as well as among children residing in underserved areas.

Importance of Early Intervention in Reducing Autistic Symptoms and Speech-Language Deficits in Children with Autism Spectrum Disorder

The intervention focused on starting treatment at an early age to develop the child’s full potential, which is known as early intervention. Given that autistic symptoms and language deficits occur at an early age and affect other areas of development in children with autistic spectrum disorder, we wanted to examine if early intervention is more effective in the reduction in autistic symptoms and language deficits in children aged 36−47 months old when compared to children 48−60 months old. The sample consisted of 29 children diagnosed with ASD who were admitted for integrative therapy. All participants were divided into two groups based on age: G1: 36−47 months old children, and G2: 48−60 months old children. To estimate the presence of autistic symptoms, we used the GARS-3, and for the assessment of speech−language abilities, we used the subscale Estimated Speech and Language Development (ESLD). Our results regarding the effect of the group on the difference in the scores at two time points showed that there was a statistically significant effect of the group on the reduction in autistic symptoms (p < 0.05) but no effect of the group on the differences in speech−language abilities between the two time points (p > 0.05). Our study highlights the importance of emphasizing the exact age when using the terms “early intervention” and “early development” in future studies and practice because it is necessary to determine and establish guidelines about which particular ages are crucial for starting treatment in certain developmental aspects.

Autistic Traits, Arousal, and Gender Features in a Nonclinical Sample of Italian Adolescents

(1) Background: Subthreshold autism is a sub-clinical pattern of autism spectrum disorder-like (ASD-like) traits, including poor social skills, cognitive rigidity, anxiety, and aloofness. These ASD-like traits are significantly more prevalent among parents and relatives of participants with autism; however, evidence suggests that subclinical autistic traits are not restricted to the family members of individuals with autism but rather are continuously distributed in the general population. Though the autistic subclinical form is perhaps prevalent among adults, little attention has been paid to the association between autistic traits and global functioning in adolescence. The aim of the present study is to investigate the subthreshold autism phenotype in adolescence and its relationship with arousal correlates, exploring gender differences emerging in the sample. (2) Methods: A sample of 725 students (293 males and 432 females; mean age 17.19) were recruited from three high schools in Southern Italy. They were assessed by the following instruments: Autism Spectrum Quotient, Adult Autism Subthreshold Spectrum, Ritvo Autism and Asperger Diagnostic Scale 14, and Hyperarousal Scale. (3) Results: In males, significant direct correlations between all dimensions of arousal and all variables related to autistic traits emerged except for the correlations between the H-Scale "Introspection score", the AQ questionnaire "Total score" (p = 0.094), and the AdAS-Spectrum questionnaire "Empathy factor" (p = 0.210); in females, significant positive correlations between all dimensions of arousal and all variables related to autistic traits emerged. (4) Conclusions: In the sample of adolescents with subclinical profiles of autistic traits, the Empathy factor of the AdAS Spectrum questionnaire was significantly higher in the male group than in the female group, underscoring lower empathic abilities in the former group. In the male group, the empathy factor did not have a statistically significant correlation with the H-scale introspection factor or with the autistic traits measured by AQ. We suppose that in male adolescents, another hypothetical factor seems to intervene in the relationship between autistic traits and arousal. Otherwise, empathy is a preponderant factor closely related to hyper-arousal responses in female adolescents with autistic traits.

The impact of educational rewards on the diagnosis of autism spectrum disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that affects social interactions and communication. The prevalence of ASD has risen dramatically in recent years, but the underlying factors leading to this rise are not clear. In this paper, we test whether changes in state-level educational policy that impact school-level resources are associated with the rise in ASD diagnostic prevalence. Early identification of ASD can improve an array of outcomes for children, and school systems play an important role with identification of the condition. It is plausible that children attending schools with better resources from state governments are more likely to receive an ASD diagnosis and presumably appropriate services. We focus on one educational policy in particular, state-level rewards, which consist of a monetary transfer from state governments to school districts. To test the impact of educational rewards on ASD diagnosis, we rely on policy variation across states and time and estimate both two-way fixed effects (TWFE) models alongside recently advanced methods in the difference-in-differences (DiD) literature. Under a baseline TWFE specification we estimate that rewards policies are associated with a 18.46% increase in ASD diagnosis. Further, using DiD methods that account for bias in settings of differential policy timing, we find that the magnitude of the effect increases to 24.8%. We believe these findings to be suggestive evidence that educational rewards policies improved the likelihood of detection and diagnosis of ASD.

Associations between parental psychiatric disorders and autism spectrum disorder in the offspring

Whether parental psychiatric disorders are associated with autism spectrum disorder (ASD) in offspring has remained inconclusive. We examined the associations of parental psychiatric disorders with ASD in offspring. This population-based case-control study used Taiwan's National Health Insurance Research Database to identify a cohort of children born from 2004 to 2017 and their parents. A total of 24,279 children with ASD (diagnostic ICD-9-CM code: 299.x or ICD-10 code F84.x) and 97,715 matched controls were included. Parental psychiatric disorders, including depressive disorders, bipolar spectrum disorders, anxiety disorders, obsessive-compulsive disorder, schizophrenia, substance use disorders, autism spectrum disorder, attention-deficit hyperactivity disorder (ADHD), and adjustment disorders were identified. Conditional logistic regressions with covariate adjustment were performed. The results suggest that parental diagnosis with any of the psychiatric disorders is associated with ASD in offspring (adjusted odds ratio [AOR] = 1.45, 95%CI: 1.40-1.51 for mothers; and AOR = 1.12, 95%CI: 1.08-1.17 for fathers). ASD in offspring was associated with schizophrenia, depressive disorders, obsessive-compulsive disorder, adjustment disorders, ADHD and ASD in both parents. The relationship between parental psychiatric disorders and the timing of the child's birth and ASD diagnosis varied across the different psychiatric disorders. The present study provides supportive evidence that parental psychiatric disorders are associated with autistic children. Furthermore, because the associations between parental psychiatric disorders and the timing of child's birth and ASD diagnosis varied across psychiatric disorders, the observed relationships may be affected by both genetic and environmental factors. Future studies are needed to disentangle the potential influence of genetic and environmental factors on the observed associations.

TF and TCF4 gene polymorphisms are linked to autism spectrum disorder: a case-control study

OBJECTIVE

Although the prevalence of autism spectrum disorder (ASD) is increasing, appropriate diagnosis and prevention strategies are still lacking. This case-control study was designed to explore the association between ASD and the rs1867503 and rs9951150 polymorphisms of the TF and TCF4 genes, respectively.

METHODS

Ninety-six children with ASD and 118 healthy children were recruited and polymerase chain reaction-restriction fragment length polymorphism technique was applied for genotyping.

RESULTS

The frequencies of the mutant allele G were 48% and 44% for the rs1867503 and rs9951150 polymorphisms, respectively. In our analysis, both TF and TCF4 polymorphisms were associated with an increased risk of developing ASD. AG heterozygotes (OR = 3.18), GG mutant homozygotes (OR = 2.62), AG + GG combined genotypes (OR = 2.98), and G mutant alleles of TF rs1867503 (OR = 1.94) were associated with a significantly elevated risk of ASD. Likewise, AG heterozygotes (OR = 2.92), GG mutant homozygotes (OR = 2.36), AG + GG combined genotypes (OR = 2.72), and G minor alleles of TCF4 rs9951150 (OR = 1.92) were associated with a significantly elevated risk of ASD.

CONCLUSIONS

Our results indicate that TF rs1867503 and TCF4 rs9951150 polymorphisms may be strongly associated with the development of ASD in Bangladeshi children.

Progress in magnetic resonance imaging of autism model mice brain

Autism spectrum disorder (ASD) is a neurodevelopmental disease characterized by social disorder and stereotypical behaviors with an increasing incidence. ASD patients are suffering from varying degrees of mental retardation and language development abnormalities. Magnetic resonance imaging (MRI) is a noninvasive imaging technology to detect brain structural and functional dysfunction in vivo, playing an important role in the early diagnosisbasic research of ASD. High-field, small-animal MRI in basic research of autism model mice has provided a new approach to research the pathogenesis, characteristics, and intervention efficacy in autism. This article reviews MRI studies of mouse models of autism over the past 20 years. Reduced gray matter, abnormal connections of brain networks, and abnormal development of white matter fibers have been demonstrated in these studies, which are present in different proportions in the various mouse models. This provides a more macroscopic view for subsequent research on autism model mice. This article is categorized under: Cognitive Biology > Genes and Environment Neuroscience > Computation Neuroscience > Genes, Molecules, and Cells Neuroscience > Development.

Maternal androgens and autism spectrum disorder in the MARBLES prospective cohort study

Background

Maternal hormonal risk factors for autism spectrum disorder (ASD) in offspring could intersect genetic and environmental risk factors.

Objectives

This analysis explored ASD risk in association with maternal testosterone, androstenedione, and dehydroepiandrosterone (DHEA) measured in first, second, and third trimesters of pregnancy.

Methods

MARBLES is a prospective pregnancy cohort study based at the MIND Institute in Northern California that enrolls mothers who have at least one child previously diagnosed with ASD and are expecting, or planning to have another child. At 36 months the younger sibling is clinically classified as having ASD, or as non-typically developing (Non-TD), or typically developing (TD). Maternal androgens during pregnancy were measured in serum samples from 196 mothers. Multivariable logistic regression models estimated risk of ASD and Non-TD in offspring compared to TD, in relation to the log-transformed maternal androgen concentrations, at each trimester.

Results

Non-significant associations were observed, and borderline significant associations were only observed in some stratified unadjusted models. Second trimester maternal testosterone was non-significantly associated with ASD in female offspring, although not after adjustment, aRR 1.54 (95% CI 0.71, 3.33), and second trimester maternal DHEA was non-significantly associated with non-TD in male offspring, again not after adjustment, aRR 0.50 (95% CI 0.21, 1.21). Secondary analysis suggested that third trimester androgen concentrations in mothers with male offspring had significant or near significant associations with their child's Social Responsiveness Scale score.

Conclusion

No significant associations were found between maternal androgen concentrations and risk of ASD or Non-TD in the child.

Examination of multiple birth as a predictor of autism symptom severity and developmental functioning in an early intervention sample

Multiple birth is one of several perinatal factors associated with increased risk for autism spectrum disorder (ASD); however, complexity in its relationship to ASD symptoms and developmental functioning remains. The present study investigated perinatal risk factors for ASD, primarily focusing on birth status, within a large early intervention sample. In particular, the relationship between ASD, perinatal factors, and the effect of birth status on developmental functioning and ASD symptom severity were examined in youth with and without ASD classification who were born singly or were the product of a multiple birth. Overall, the presence of other perinatal risk factors, including prematurity, low birth weight, and advanced parental age, was primarily related to birth status and not to ASD classification, while severity of ASD symptoms and developmental impairments were primarily related to ASD classification and not to birth status. Study findings and implications for early screening of children with developmental delays are discussed.

Pharmacological effects and therapeutic potential of natural compounds in neuropsychiatric disorders: An update

Neuropsychiatric diseases are a group of disorders that cause significant morbidity and disability. The symptoms of psychiatric disorders include anxiety, depression, eating disorders, autism spectrum disorders (ASD), attention-deficit/hyperactivity disorder, and conduct disorder. Various medicinal plants are frequently used as therapeutics in traditional medicine in different parts of the world. Nowadays, using medicinal plants as an alternative medication has been considered due to their biological safety. Despite the wide range of medications, many patients are unable to tolerate the side effects and eventually lose their response. By considering the therapeutic advantages of medicinal plants in the case of side effects, patients may prefer to use them instead of chemical drugs. Today, the use of medicinal plants in traditional medicine is diverse and increasing, and these plants are a precious heritage for humanity. Investigation about traditional medicine continues, and several studies have indicated the basic pharmacology and clinical efficacy of herbal medicine. In this article, we discuss five of the most important and common psychiatric illnesses investigated in various studies along with conventional therapies and their pharmacological therapies. For this comprehensive review, data were obtained from electronic databases such as MedLine/PubMed, Science Direct, Web of Science, EMBASE, DynaMed Plus, ScienceDirect, and TRIP database. Preclinical pharmacology studies have confirmed that some bioactive compounds may have beneficial therapeutic effects in some common psychiatric disorders. The mechanisms of action of the analyzed biocompounds are presented in detail. The bioactive compounds analyzed in this review are promising phytochemicals for adjuvant and complementary drug candidates in the pharmacotherapy of neuropsychiatric diseases. Although comparative studies have been carefully reviewed in the preclinical pharmacology field, no clinical studies have been found to confirm the efficacy of herbal medicines compared to FDA-approved medicines for the treatment of mental disorders. Therefore, future clinical studies are needed to accelerate the potential use of natural compounds in the management of these diseases.

Randomized Double-Blind Crossover Study for Evaluating a Probiotic Mixture on Gastrointestinal and Behavioral Symptoms of Autistic Children

Autism spectrum disorders (ASDs) represent a diagnostic challenge with a still partially uncertain etiology, in which genetic and environmental factors have now been assessed. Among the hypotheses underlying the involvement of biological and environmental factors, the gut–brain axis is of particular interest in autism spectrum disorders. Several studies have highlighted the related incidence of particular gastrointestinal symptoms (GISs) in children suffering from ASDs. Probiotics have shown success in treating several gastrointestinal dysbiotic disorders; therefore, it is plausible to investigate whether they can alleviate behavioral symptoms as well. On these bases, a randomized double-blind crossover study with a placebo was conducted, evaluating the effects of a mixture of probiotics in a group of 61 subjects aged between 24 months and 16 years old with a diagnosis of ASD. Behavioral evaluation was performed through the administration of a questionnaire including a Parenting Stress Index (PSI) test and the Vineland Adaptive Behavior Scale (VABS). The Psycho-Educational Profile and the Autism Spectrum Rating Scale (ASRS) were also evaluated. Microbial composition analyses of fecal samples of the two groups was also performed. The study showed significant improvements in GISs, communication skills, maladaptive behaviors, and perceived parental stress level after the administration of probiotics. Microbiome alpha diversity was comparable between treatment arms and no significant differences were found, although beta diversity results were significantly different in the treatment group between T0 and T1 time points. Streptococcus thermophilus, Bifidobacterium longum, Limosilactobacillus fermentum, and Ligilactobacillus salivarius species were identified as some of the most discriminant taxa positively associated with T1 samples. This preliminary study corroborates the relationship between intestinal microbiota and ASD recently described in the literature.

DNA Methylation Profiles of GAD1 in Human Cerebral Organoids of Autism Indicate Disrupted Epigenetic Regulation during Early Development

DNA methylation profiling has become a promising approach towards identifying biomarkers of neuropsychiatric disorders including autism spectrum disorder (ASD). Epigenetic markers capture genetic risk factors and diverse exogenous and endogenous factors, including environmental risk factors and complex disease pathologies. We analysed the differential methylation profile of a regulatory region of the GAD1 gene using cerebral organoids generated from induced pluripotent stem cells (iPSCs) from adults with a diagnosis of ASD and from age- and gender-matched healthy individuals. Both groups showed high levels of methylation across the majority of CpG sites within the profiled GAD1 region of interest. The ASD group exhibited a higher number of unique DNA methylation patterns compared to controls and an increased CpG-wise variance. We detected six differentially methylated CpG sites in ASD, three of which reside within a methylation-dependent transcription factor binding site. In ASD, GAD1 is subject to differential methylation patterns that may not only influence its expression, but may also indicate variable epigenetic regulation among cells.

COVID-19 and changes in college student educational expectations and health by disability status

This study examines the implications of the coronavirus pandemic for college students' health and education, with special attention to variation by disability status. Disaster research supports the hypothesis that students with disabilities will experience higher-than-usual levels of pandemic-related stress, which could lead to re-evaluations of their educational expectations and declines in health. We evaluate this hypothesis by modeling changes in students’ (1) mental and physical health and (2) educational expectations during the first year (spring of 2020 to spring of 2021) of the pandemic, using survey data collected from a population-based sample of college students in the state of Indiana. Although we observe across-the-board declines in both domains, students with disabilities were especially vulnerable. Mediation analyses suggest that differential exposure to financial and illness-related stressors is partially to blame, explaining a significant portion of the group differences between students with and without disabilities. We interpret these results as evidence of the unique vulnerabilities associated with disability status and its wide-ranging importance as a dimension of social stratification.

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College students with disabilities were more likely to experience declines in mental and physical health during the first year of the pandemic than students without disabilities.

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Students with disabilities were also more likely to report declines in their educational expectations.

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Similar patterns were evident for students with an autism spectrum disorder (ASD).

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Differential exposure to financial and illness related stressors explains a significant portion of the group differences between students with and without disabilities.

Prefrontal Circuits guiding Social Preference: Implications in Autism Spectrum Disorder

Although Autism Spectrum Disorder (ASD) is increasing in diagnostic prevalence, treatment options are inadequate largely due to limited understanding of ASD's underlying neural mechanisms. Contributing to difficulties in treatment development is the vast heterogeneity of ASD, from physiological causes to clinical presentations. Recent studies suggest that distinct genetic and neurological alterations may converge onto similar underlying neural circuits. Therefore, an improved understanding of neural circuit-level dysfunction in ASD may be a more productive path to developing broader treatments that are effective across a greater spectrum of ASD. Given the social preference behavioral deficits commonly seen in ASD, dysfunction in circuits mediating social preference may contribute to the atypical development of social cognition. We discuss some of the animal models used to study ASD and examine the function and effects of dysregulation of the social preference circuits, notably the medial prefrontal cortex-amygdala and the medial prefrontal cortex-nucleus accumbens circuits, in these animal models. Using the common circuits underlying similar behavioral disruptions of social preference behaviors as an example, we highlight the importance of identifying disruption in convergent circuits to improve the translational success of animal model research for ASD treatment development.

Access to Care for US Children with Co-Occurrence of Autism Spectrum Disorder and Epilepsy

Epilepsy is a common comorbidity among children with autism spectrum disorder (ASD). There is a lack of understanding of the inequality in access to care for children with co-occurring ASD and epilepsy (ASD-EP). The purpose of this study is to examine key indicators for access to care and care coordination for children with ASD-EP in the US National Survey of Children’s Health (NSCH). Data were collected from the 2017–2019 NSCH. Our analytic sample included children with ASD without epilepsy (N = 2150), children with both ASD and epilepsy (N = 143), and children with epilepsy without ASD (N = 711). The dependent variables included important access to care indicators such as having usual sources of care, having adequate coverage, being frustrated in efforts to get service, and receiving care coordination. The independent variables included ASD-EP status, child demographics, and an intellectual disability (ID) diagnosis. Our results show that demographic characteristics such as sex, race, income level, and insurance type affect access to care. Inadequate access to healthcare was significantly higher among female children, children from low-income families, and children with ID. The access barriers among children with ASD-EP were more likely due to the interplay of multiple clinical and individual factors.

Click-evoked auditory brainstem responses and autism spectrum disorder: a meta-analytic investigation of disorder specificity

BACKGROUND

Click-evoked auditory brainstem response (ABR) alterations are associated with autism spectrum disorder (ASD), but the specificity of these findings to the disorder is unclear. We therefore performed a meta-analysis on ABRs and attention-deficit/hyperactivity disorder (ADHD), a neurodevelopmental disorder that shares some etiologic and symptom overlap with ASD.

METHODS

Seven papers compared ABR latency components (I, III, V, I-III, III-V, and I-V) between participants with and without ADHD. We used random-effects regression to generate component-specific estimates (Hedges's g) that adjusted for study sample sizes and the number of studies contributing to each estimate. We compared these estimates to our recently published meta-analysis of ABRs and ASD.

RESULTS

All ADHD studies employed cross-sectional designs. ADHD was associated with longer latencies for waves III and V (g = 0.6, 95% confidence interval (CI) 0.3, 1.0 and g = 0.6, 95% CI 0.3, 0.9) and waves I-III and I-V (g = 0.7, 95% CI 0.2, 1.3 and g = 0.6, 95% CI 0.3, 1.0). Effect sizes from the ASD and ADHD meta-analyses did not differ from each other.

CONCLUSIONS

Similar patterns of ABR alterations are observed in ADHD and ASD. However, studies rarely screen for middle ear dysfunction or hearing loss and rely upon cross-sectional designs. Addressing these issues will inform the viability of ABRs as a prognostic and/or etiologic biomarker for these disorders.

IMPACT

Click-evoked ABR alterations are associated with ASD, but the specificity of these findings to the disorder is unclear. We therefore performed a meta-analysis of the association between ABRs and ADHD, a disorder that shares some etiologic and symptom overlap with ASD. ADHD was associated with longer ABR latencies for several components. These components are identical to those implicated in ASD. Effect sizes were similar in magnitude across disorders. The viability of ABRs as prognostic and/or etiologic biomarkers for neurodevelopmental risk requires addressing limitations in the literature (e.g., cross-sectional data, non-standardized ABR protocols, minimal characterization of symptom heterogeneity).

Influences of the Immune System and Microbiome on the Etiology of ASD and GI Symptomology of Autistic Individuals

Autism Spectrum Disorder is a developmental condition associated with impairments in communication and social interactions, and repetitive and restricted behavior or interests. Autistic individuals are more likely to experience gastrointestinal (GI) symptoms than neurotypical individuals. This may be partially due to dysbiosis of the gut microbiome. In this article, we describe the interaction of the microbiome and immune system on autism etiology. We also summarize the links between the microbiome and gastrointestinal and related symptoms among autistic individuals. We report that microbial interventions, including diet, probiotics, antibiotics, and fecal transplants, and immune-modulating therapies such as cytokine blockade during the preconception, pregnancy, and postnatal period may impact the neurodevelopment, behavior, and gastrointestinal health of autistic individuals.

Is There an Association between the Use of Epidural Analgesia during Labor and the Development of Autism Spectrum Disorder in the Offspring?-A Review of the Literature

Autism spectrum disorders (ASDs) are multifactorial and complex neurodevelopmental conditions usually diagnosed in the early childhood. The etiology of ASDs is commonly described as a genetic predisposition combined with an environmental impact. As a result of broadening of the diagnostic criteria the prevalence of ASDs has been increasing worldwide and the search for the modifiable factors is still on-going. Epidural analgesia (ELA) provides effective pain relief during labor and is currently the most preferred method of anesthesia during the delivery. The safety of the procedure is well-discussed and documented; nonetheless, in 2020 a single population-based study indicated an association between the use of ELA during labor and newborn risk of ASD development, which led to widespread concern. To explore the possible association between the ELA and ASD occurrence in the offspring several studies in different countries have been conducted to date. In this review we aimed to summarize the current state of knowledge concerning the association between the use of epidural analgesia during labor and risk of ASD. In conclusion, the literature review indicates that there is no significant association.

A Study of the Genomic Variations Associated with Autistic Spectrum Disorders in a Russian Cohort of Patients Using Whole-Exome Sequencing

This study provides new data on the whole-exome sequencing of a cohort of children with autistic spectrum disorders (ASD) from an underexplored Russian population. Using both a cross-sectional approach involving a control cohort of the same ancestry and an annotation-based approach involving relevant public databases, we explored exonic single nucleotide variants and copy-number variation potentially involved in the manifestation of ASD. The study results reveal new potential ASD candidate-variants found in the studied Russian cohort and show a high prevalence of common ASD-associated genomic variants, especially those in the genes known to be associated with the manifestation of intellectual disabilities. Our screening of an ASD cohort from a previously understudied population allowed us to flag at least a few novel genes (IGLJ2, FAM21A, OR11H12, HIP1, PRAMEF10, and ZNF717) regarding their potential involvement in ASD.

Sex Differences in Autism Spectrum Disorder: Diagnostic, Neurobiological, and Behavioral Features

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental disorder with a worldwide prevalence of about 1%, characterized by impairments in social interaction, communication, repetitive patterns of behaviors, and can be associated with hyper- or hypo-reactivity of sensory stimulation and cognitive disability. ASD comorbid features include internalizing and externalizing symptoms such as anxiety, depression, hyperactivity, and attention problems. The precise etiology of ASD is still unknown and it is undoubted that the disorder is linked to some extent to both genetic and environmental factors. It is also well-documented and known that one of the most striking and consistent finding in ASD is the higher prevalence in males compared to females, with around 70% of ASD cases described being males. The present review looked into the most significant studies that attempted to investigate differences in ASD males and females thus trying to shade some light on the peculiar characteristics of this prevalence in terms of diagnosis, imaging, major autistic-like behavior and sex-dependent uniqueness. The study also discussed sex differences found in animal models of ASD, to provide a possible explanation of the neurological mechanisms underpinning the different presentation of autistic symptoms in males and females.

Contributing factors to healthcare costs in individuals with autism spectrum disorder: a systematic review

BACKGROUND

Individuals with autism spectrum disorder (ASD) are more likely to use healthcare than their counterparts without disabilities, which imposes high medical costs to families and health systems. This study aimed to investigate healthcare costs and its determinants among individuals with ASD.

METHODS

In this systematic review, we searched online databases (Web of Science, Medline through PubMed and Scopus) for observational and experimental studies that included data on service use and costs associated with ASD and published between January 2000 and May 2021. Exclusion criteria included non-English language articles, duplicates, abstracts, qualitative studies, gray literature, and non-original papers (e.g., letters to editors, editorials, reviews, etc.).

RESULTS

Our searches yielded 4015 articles screened according to PRISMA guidelines. Of 4015 studies identified, 37 articles from 10 countries were eligible for final inclusion. Therapeutic interventions, outpatient visits and medications constituted the largest proportion of direct medical expenditure on individuals with ASD. Included studies suggest lack of health insurance, having associated morbidities, more severe symptoms, younger age groups and lower socioeconomic status (SES) are associated with higher medical expenditure in individuals with ASD.

CONCLUSIONS

This systematic review identified a range of factors, including lower SES and lack of health insurance, which are associated with higher healthcare costs in people with ASD. Our study supports the formulation of policy options to reduce financial risks in families of individuals with ASD in countries which do not have a tax-based or universal health coverage system.

A Scoping Literature Review of the Relation between Nutrition and ASD Symptoms in Children

Autism spectrum disorder (ASD) is characterized by impairments in social interaction, communication skills, and repetitive and restrictive behaviors and interests. Even though there is a biological basis for an effect of specific nutrition factors on ASD symptoms and there is scientific literature available on this relationship, whether nutrition factors could play a role in ASD treatment is unclear. The goal of the current literature review was to summarize the available scientific literature on the relation between nutrition and autism spectrum disorder (ASD) symptoms in childhood, and to formulate practical dietary guidelines. A comprehensive search strategy including terms for ASD, nutrition factors (therapeutic diets, dietary patterns, specific food products, fatty acids and micronutrients) and childhood was developed and executed in six literature databases (Cinahl, Cochrane, Ovid Embase, PsycInfo, PubMed and Web of Science). Data from meta-analyses, systematic reviews and original studies were qualitatively summarized. A total of 5 meta-analyses, 29 systematic reviews and 27 original studies were retrieved that focused on therapeutic diets, specific food products, fatty acids and micronutrients and ASD symptoms during childhood. Results of the available studies were sparse and inconclusive, and hence, no firm conclusions could be drawn. There is currently insufficient evidence for a relation between nutrition and ASD symptoms in childhood, making it impossible to provide practical nutrition guidelines; more methodological sound research is needed.

Early Prediction and Evaluation of Risk of Autism Spectrum Disorders

Autism is a neuro-developmental condition that first appears at less than three years of age. Autism spectrum disorders (ASD) include several symptoms, such as social communication impairment, stereotyping behaviors, speech abnormalities, and impairment of eye contact. Its prevalence has increased recently, and several factors play a role in increasing the risk of autism. Multiple studies and research explain the factors affecting the rate of autism, and in this article, we will review most of these factors. The aim of this review article is to increase awareness of the problem of autism and provide scientifically relevant information about the etiology, pathogenesis, risk factors, and management of ASD. Our perception of autism has evolved over time. A few years ago, the condition was nothing more than an unrecognized developmental delay, generally with intellectual disabilities. Today, it is recognized as a major public health issue and a topic of much research. Researchers have struggled to find a cause for ASD, and numerous treatments have been developed to maximize the potential to learn and become socially fluent, no matter how strong the impairments may be. Although there is no cure, there have been significant strides in identifying and developing treatments. Early prediction of autism is beneficial in an individual's treatment, which can be carried out by recognizing the risk factors of infants, thus leading to improved outcomes or even a complete cure. The prevalence of ASD has increased, and earlier prediction leads to the best outcomes.

Pre- and Postnatal Fine Particulate Matter Exposure and Childhood Cognitive and Adaptive Function

Increasing evidence exists for an association between early life fine particulate matter (PM_2.5) exposure and several neurodevelopmental outcomes, including autism spectrum disorder (ASD); however, the association between PM_2.5 and adaptive and cognitive function remains poorly understood. Participants included 658 children with ASD, 771 with a non-ASD developmental disorder, and 849 population controls from the Study to Explore Early Development. Adaptive functioning was assessed in ASD cases using the Vineland Adaptive Behavior Scales (VABS); cognitive functioning was assessed in all groups using the Mullen Scales of Early Learning (MSEL). A satellite-based model was used to assign PM_2.5 exposure averages during pregnancy, each trimester, and the first year of life. Linear regression was used to estimate beta coefficients and 95% confidence intervals, adjusting for maternal age, education, prenatal tobacco use, race-ethnicity, study site, and season of birth. PM_2.5 exposure was associated with poorer VABS scores for several domains, including daily living skills and socialization. Associations were present between prenatal PM_2.5 and lower MSEL scores for all groups combined; results were most prominent for population controls in stratified analyses. These data suggest that early life PM_2.5 exposure is associated with specific aspects of cognitive and adaptive functioning in children with and without ASD.

LRFN5 locus structure is associated with autism and influenced by the sex of the individual and locus conversions

LRFN5 is a regulator of synaptic development and the only gene in a 5.4 Mb mammalian‐specific conserved topologically associating domain (TAD); the LRFN5 locus. An association between locus structural changes and developmental delay (DD) and/or autism was suggested by several cases in DECIPHER and own records. More significantly, we found that maternal inheritance of a specific LRFN5 locus haplotype segregated with an identical type of autism in distantly related males. This autism‐susceptibility haplotype had a specific TAD pattern. We also found a male/female quantitative difference in the amount histone‐3‐lysine‐9‐associated chromatin around the LRFN5 gene itself (p < 0.01), possibly related to the male‐restricted autism susceptibility. To better understand locus behavior, the prevalence of a 60 kb deletion polymorphism was investigated. Surprisingly, in three cohorts of individuals with DD (n = 8757), the number of deletion heterozygotes was 20%–26% lower than expected from Hardy–Weinberg equilibrium. This suggests allelic interaction, also because the conversions from heterozygosity to wild‐type or deletion homozygosity were of equal magnitudes. Remarkably, in a control group of medical students (n = 1416), such conversions were three times more common (p = 0.00001), suggesting a regulatory role of this allelic interaction. Taken together, LRFN5 regulation appears unusually complex, and LRFN5 dysregulation could be an epigenetic cause of autism.

Educator Attitudes Towards the Inclusion of Students with Autism Spectrum Disorders in Mainstream Education: a Systematic Review

Educator attitudes towards inclusive education impact its success. Attitudes differ depending on the SEN cohort, and so the current systematic review is the first to focus solely on students with autism spectrum disorders (ASD). Seven databases searched yielded 13 relevant articles. The majority reported positive educator attitudes towards ASD inclusion but with considerable variety in the measures used. There were mixed findings regarding the impact of training and experience on attitudes but, where measured, higher self-efficacy was related to positive attitudes. In summary, educator ASD inclusion attitudes are generally positive but we highlight the need to move towards more homogeneous attitudinal measures. Further research is needed to aggregate data on attitudes towards SEN cohorts other than those with ASD.

OUP accepted manuscript

Multiple pieces of evidence support the prenatal predisposition of autism spectrum disorder (ASD). Nevertheless, robust data about abnormalities in foetuses later developing into children diagnosed with ASD are lacking. Prenatal ultrasound is an excellent tool to study abnormal foetal development as it is frequently used to monitor foetal growth and identify foetal anomalies throughout pregnancy. We conducted a retrospective case-sibling-control study of children diagnosed with ASD (cases); their own typically developing, closest-in-age siblings (TDS); and typically developing children from the general population (TDP), matched by year of birth, sex and ethnicity to investigate the association between ultrasonography foetal anomalies and ASD. The case group was drawn from all children diagnosed with ASD enrolled at the National Autism Research Center of Israel. Foetal ultrasound data from the foetal anatomy survey were obtained from prenatal ultrasound clinics of Clalit Health Services in southern Israel. The study comprised 659 children: 229 ASD, 201 TDS and 229 TDP. Ultrasonography foetal anomalies were found in 29.3% of ASD cases versus only 15.9% and 9.6% in the TDS and TDP groups [adjusted odds ratio (aOR) = 2.23, 95% confidence interval (CI) = 1.32-3.78, and aOR = 3.50, 95%CI = 2.07-5.91, respectively]. Multiple co-occurring ultrasonography foetal anomalies were significantly more prevalent among ASD cases. Ultrasonography foetal anomalies in the urinary system, heart, and head and brain were the most significantly associated with ASD diagnosis (aORUrinary = 2.08, 95%CI = 0.96-4.50 and aORUrinary = 2.90, 95%CI = 1.41-5.95; aORHeart = 3.72, 95%CI = 1.50-9.24 and aORHeart = 8.67, 95%CI = 2.62-28.63; and aORHead&Brain = 1.96, 95%CI = 0.72-5.30 and aORHead&Brain = 4.67, 95%CI = 1.34-16.24; versus TDS and TDP, respectively). ASD females had significantly more ultrasonography foetal anomalies than ASD males (43.1% versus 25.3%, P = 0.013) and a higher prevalence of multiple co-occurring ultrasonography foetal anomalies (15.7% versus 4.5%, P = 0.011). No sex differences were seen among TDS and TDP controls. ASD foetuses were characterized by a narrower head and a relatively wider ocular-distance versus TDP foetuses (ORBPD = 0.81, 95%CI = 0.70-0.94, and aOROcular distance = 1.29, 95%CI = 1.06-1.57). Ultrasonography foetal anomalies were associated with more severe ASD symptoms. Our findings shed important light on the multiorgan foetal anomalies associated with ASD.