White matter development and language abilities during infancy in autism spectrum disorder.

White matter (WM) fiber tract differences are present in autism spectrum disorder (ASD) and could be important markers of behavior. One of the earliest phenotypic differences in ASD are language atypicalities. Although language has been linked to WM in typical development, no work has evaluated this association in early ASD. Participants came from the Infant Brain Imaging Study and included 321 infant siblings of children with ASD at high likelihood (HL) for developing ASD; 70 HL infants were later diagnosed with ASD (HL-ASD), and 251 HL infants were not diagnosed with ASD (HL-Neg). A control sample of 140 low likelihood infants not diagnosed with ASD (LL-Neg) were also included. Infants contributed expressive language, receptive language, and diffusion tensor imaging data at 6-, 12-, and 24 months. Mixed effects regression models were conducted to evaluate associations between WM and language trajectories. Trajectories of microstructural changes in the right arcuate fasciculus were associated with expressive language development. HL-ASD infants demonstrated a different developmental pattern compared to the HL-Neg and LL-Neg groups, wherein the HL-ASD group exhibited a positive association between WM fractional anisotropy and language whereas HL-Neg and LL-Neg groups showed weak or no association. No other fiber tracts demonstrated significant associations with language. In conclusion, results indicated arcuate fasciculus WM is linked to language in early toddlerhood for autistic toddlers, with the strongest associations emerging around 24 months. To our knowledge, this is the first study to evaluate associations between language and WM development during the pre-symptomatic period in ASD.

Associations between early trajectories of amygdala development and later school-age anxiety in two longitudinal samples.

Amygdala function is implicated in the pathogenesis of autism spectrum disorder (ASD) and anxiety. We investigated associations between early trajectories of amygdala growth and anxiety and ASD outcomes at school age in two longitudinal studies: high- and low-familial likelihood for ASD, Infant Brain Imaging Study (IBIS, n = 257) and typically developing (TD) community sample, Early Brain Development Study (EBDS, n = 158). Infants underwent MRI scanning at up to 3 timepoints from neonate to 24 months. Anxiety was assessed at 6-12 years. Linear multilevel modeling tested whether amygdala volume growth was associated with anxiety symptoms at school age. In the IBIS sample, children with higher anxiety showed accelerated amygdala growth from 6 to 24 months. ASD diagnosis and ASD familial likelihood were not significant predictors. In the EBDS sample, amygdala growth from birth to 24 months was associated with anxiety. More anxious children had smaller amygdala volume and slower rates of amygdala growth. We explore reasons for the contrasting results between high-familial likelihood for ASD and TD samples, grounding results in the broader literature of variable associations between early amygdala volume and later anxiety. Results have the potential to identify mechanisms linking early amygdala growth to later anxiety in certain groups.

Improving autism identification and support for individuals assigned female at birth: clinical suggestions and research priorities.

Emerging evidence suggests that the higher prevalence of autism in individuals who are assigned male than assigned female at birth results from both biological factors and identification biases. Autistic individuals who are assigned female at birth (AFAB) and those who are gender diverse experience health disparities and clinical inequity, including late or missed diagnosis and inadequate support. In this Viewpoint, an international panel of clinicians, scientists, and community members with lived experiences of autism reviewed the challenges in identifying autism in individuals who are AFAB and proposed clinical and research directions to promote the health, development, and wellbeing of autistic AFAB individuals. The recognition challenges stem from the interplay between cognitive differences and nuanced or different presentations of autism in some AFAB individuals; expectancy, gender-related, and autism-related biases held by clinicians; and social determinants. We recommend that professional development for clinicians be supported by health-care systems, professional societies, and governing bodies to improve equitable access to assessment and earlier identification of autism in AFAB individuals. Autistic AFAB individuals should receive tailored support in education, identity development, health care, and social and professional sense of belonging.

Comparative strengths and challenges on face-to-face and computer-based attention tasks in autistic and neurotypical toddlers.

The objectives were to compare patterns of visual attention in toddlers diagnosed with autism spectrum disorder (ASD) as compared to their sex- and age-matched neurotypical (NT) peers. Participants included 23 toddlers with ASD and 19 NT toddlers (mean age: 25.52 versus 25.21 months, respectively) assessed using computerized tasks to measure sustained attention, disengaging attention, and cognitive control, as well as an in-person task to assess joint attention. Toddlers in the ASD group showed increased looking durations on the sustained attention task, as well as reduced frequencies of responding to and initiating joint attention compared to NT peers, but showed no differences on tasks of disengaging attention and cognitive control. The results suggest that toddlers with ASD have attentional strengths that may provide a foundation for building attention, communicative, and ultimately, academic skills.

Autistic Regression and Exposure to Industrial Chemicals: Preliminary Observations.

Exposure to industrial pollutants is a potential risk factor not fully explored in ASD with regression (ASD+R). We studied geographical collocation patterns of industrial air chemical emissions and the location of homes of children with ASD+R at different exposure times, compared with ASD cases without regression (ASD-R). Fifteen of 111 emitted chemicals collocated with ASD+R, and 65 with ASD-R. ASD+R collocated more strongly with different neurotoxicants/immunotoxicants a year before diagnosis, whereas ASD-R were moderately collocated with chemicals across all exposure periods. This preliminary exploratory analysis of differences in exposure patterns raises a question regarding potential pathophysiological differences between the conditions.

Indigenous Autism in Canada: A Scoping Review.

Currently there is a severe lack of research on autism and Indigenous people in Canada. This scoping review explores this literature gap and assesses the same literature from an Indigenous perspective. Scoping reviews are an effective means to explore the literature in a specific area, in this case, autism and Indigenous people in Canada. We explored existing literature as it pertains to Indigenous populations and autism in Canada. To support this review, the Indigenous Quality Assessment Tool (QAT) was adapted to appraise the quality of literature. In total, there were a total of 212 articles identified of which 24 met the inclusion criteria: (1) some focus on autism, (2) a component specific to Indigenous people, and (3) specific to Canada. Of the 24 articles and reports, 15 were peer-reviewed and the rest considered grey literature. Most articles focused on program delivery with some literature using primary data (quantitative and/or qualitative). Overall, the quality of the research was appraised as poor, as determined by the QAT. Findings reaffirm the critical need for research that addresses autism in Indigenous communities within Canada and show the importance of having research done in full partnership with, or led by, Indigenous people.

Influence of a Brief Autism Education Intervention on Peer Engagement and Inclusion At Mainstream Day Camps: A Mixed-Methods Pilot Study.

To explore the benefits of a brief autism education intervention on peer engagement and inclusion of autistic children at day camps. A convergent, parallel, two-arm (intervention/no intervention), non-randomized, mixed-methods design was used. The individualized, peer-directed, 5-10 min intervention included four components: (1) diagnostic label, (2) description and purpose of unique behaviors, (3) favorite activities and interests, and (4) strategies to engage. A timed-interval behavior-coding system was used to evaluate engagement between each autistic camper and their peers based on videos taken at camp (days 1, 2, 5). Interviews with campers and camp staff explored why changes in targeted outcomes may have occurred. Percent intervals in which the autistic campers were jointly engaged with peers improved in the intervention group (n = 10) and did not change in the control group (n = 5). A large between group intervention effect occurred by day 5 (Z = - 1.942, η2 = 0.29). Interviews (5 autistic campers, 34 peers, 18 staff) done on the last day of camp in the intervention group garnered three themes: (1) Changed behavioral attribution, (2) Knowledge facilitates understanding and engagement, and (3) (Mis)perceptions of increased inclusion. A brief educational intervention that includes individualized explanatory information and strengths-based strategies might improve peers' understanding of and social engagement with autistic children in community programs such as camps.

Behavioural reactions to an emotion evoking task in infants at increased likelihood for autism spectrum disorder.

Infants at increased likelihood for autism spectrum disorder (ASD) exhibit more negative affect and avoidance behaviour than typically developing infants, and children with ASD express fear differently than typically developing peers. We examined behavioural reactions to emotion-evoking stimuli in infants at increased familial likelihood for ASD. Participants included 55 increased likelihood (IL) infants (i.e., siblings of children diagnosed with ASD) and 27 typical likelihood (TL) infants (i.e., no family history of ASD). At 18 months, we showed infants two masks that commonly elicit fearful responses in older children and examined potential behavioural differences in approach, avoidance, 'freezing', crying, gaze aversion, and smiling. At 24 months, infants were assessed with the Toddler Module of the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2). Results of video-based coding showed that (1) IL infants exhibited more intense avoidance behaviour than TL infants in response to masks, and (2) intensity of avoidance and duration of freezing were positively correlated with ADOS-2 symptom severity scores. Findings suggest that differences in response to emotion-eliciting stimuli may predict later ASD symptoms. Such behavioural differences may inform early detection and intervention in ASD.

Association of Sex With Neurobehavioral Markers of Executive Function in 2-Year-Olds at High and Low Likelihood of Autism.

Importance: Children with autism and their siblings exhibit executive function (EF) deficits early in development, but associations between EF and biological sex or early brain alterations in this population are largely unexplored. Objective: To investigate the interaction of sex, autism likelihood group, and structural magnetic resonance imaging alterations on EF in 2-year-old children at high familial likelihood (HL) and low familial likelihood (LL) of autism, based on having an older sibling with autism or no family history of autism in first-degree relatives. Design, Setting, and Participants: This prospective cohort study assessed 165 toddlers at HL (n = 110) and LL (n = 55) of autism at 4 university-based research centers. Data were collected from January 1, 2007, to December 31, 2013, and analyzed between August 2021 and June 2022 as part of the Infant Brain Imaging Study. Main Outcomes and Measures: Direct assessments of EF and acquired structural magnetic resonance imaging were performed to determine frontal lobe, parietal lobe, and total cerebral brain volume. Results: A total of 165 toddlers (mean [SD] age, 24.61 [0.95] months; 90 [54%] male, 137 [83%] White) at HL for autism (n = 110; 17 diagnosed with ASD) and LL for autism (n = 55) were studied. The toddlers at HL for autism scored lower than the toddlers at LL for autism on EF tests regardless of sex (mean [SE] B = -8.77 [4.21]; 95% CI, -17.09 to -0.45; η2p = 0.03). With the exclusion of toddlers with autism, no group (HL vs LL) difference in EF was found in boys (mean [SE] difference, -7.18 [4.26]; 95% CI, 1.24-15.59), but EF was lower in HL girls than LL girls (mean [SE] difference, -9.75 [4.34]; 95% CI, -18.32 to -1.18). Brain-behavior associations were examined, controlling for overall cerebral volume and developmental level. Sex differences in EF-frontal (B [SE] = 16.51 [7.43]; 95% CI, 1.36-31.67; η2p = 0.14) and EF-parietal (B [SE] = 17.68 [6.99]; 95% CI, 3.43-31.94; η2p = 0.17) associations were found in the LL group but not the HL group (EF-frontal: B [SE] = -1.36 [3.87]; 95% CI, -9.07 to 6.35; η2p = 0.00; EF-parietal: B [SE] = -2.81 [4.09]; 95% CI, -10.96 to 5.34; η2p = 0.01). Autism likelihood group differences in EF-frontal (B [SE] = -9.93 [4.88]; 95% CI, -19.73 to -0.12; η2p = 0.08) and EF-parietal (B [SE] = -15.44 [5.18]; 95% CI, -25.86 to -5.02; η2p = 0.16) associations were found in girls not boys (EF-frontal: B [SE] = 6.51 [5.88]; 95% CI, -5.26 to 18.27; η2p = 0.02; EF-parietal: B [SE] = 4.18 [5.48]; 95% CI, -6.78 to 15.15; η2p = 0.01). Conclusions and Relevance: This cohort study of toddlers at HL and LL of autism suggests that there is an association between sex and EF and that brain-behavior associations in EF may be altered in children at HL of autism. Furthermore, EF deficits may aggregate in families, particularly in girls.

Severe obesity and global developmental delay in preschool children: Findings from a Canadian Paediatric Surveillance Program study.

Background: The co-presentation of severe obesity (SO) and global developmental delay (GDD) in Canadian preschool children has not been examined. However, SO and GDD may require syndromic diagnoses and unique management considerations. Objectives: To determine (1) minimum incidence; (2) age of onset and risk factors; and (3) health care utilization for co-presenting SO and GDD. Methods: Through the Canadian Paediatric Surveillance Program (CPSP), a monthly form was distributed to participants from February 2018 to January 2020 asking for reports of new cases of SO and GDD among children ≤5 years of age. We performed descriptive statistics for quantitative questions and qualitative content analysis for open-ended questions. Results: Forty-seven cases (64% male; 51% white; mean age: 3.5 ± 1.2 years) were included. Age of first weight concern was 2.5 ± 1.3 years and age of GDD diagnosis was 2.7 ± 1.4 years. Minimum incidence of SO and GDD was 3.3 cases per 100,000 for ≤5 years of age per year. Identified problems included school and/or behavioural problems (n = 17; 36%), snoring (n = 14; 30%), and asthma/recurrent wheeze (n = 10; 21%). Mothers of 32% of cases (n = 15) had obesity and 21% of cases (n = 10) received neonatal intensive care. Microarray was ordered for 57% (n = 27) of children. A variety of clinicians and services were accessed. As reported by CPSP participants, challenges faced by families and health service access were barriers to care. Conclusion: Children with SO and GDD have multiple comorbidities, and require early identification and referral to appropriate services. These cases may also benefit from additional testing to rule out known genetic obesity syndromes.

Sensory Profiles in Relation to Later Adaptive Functioning Among Toddlers at High-Familial Likelihood for Autism.

This study investigated the extent to which sensory responsivity in infancy contributes to adaptive behavior development among toddlers at high-familial likelihood for autism. Prospective, longitudinal data were analyzed for 218 children, 58 of whom received an autism diagnosis. Results indicated that sensory profiles at age one year (hyperresponsivity, sensory seeking) were negatively associated with later adaptive behavior, particularly for socialization, at age 3 years regardless of diagnostic status. These results suggest that early differences in sensory responsivity may have downstream developmental consequences related to social development among young children with high-familial likelihood for autism.

Language exposure during infancy is negatively associated with white matter microstructure in the arcuate fasciculus.

Decades of research have established that the home language environment, especially quality of caregiver speech, supports language acquisition during infancy. However, the neural mechanisms behind this phenomenon remain under studied. In the current study, we examined associations between the home language environment and structural coherence of white matter tracts in 52 typically developing infants from English speaking homes in a western society. Infants participated in at least one MRI brain scan when they were 3, 6, 12, and/or 24 months old. Home language recordings were collected when infants were 9 and/or 15 months old. General linear regression models indicated that infants who heard the most adult words and participated in the most conversational turns at 9 months of age also had the lowest fractional anisotropy in the left posterior parieto-temporal arcuate fasciculus at 24 months. Similarly, infants who vocalized the most at 9 months also had the lowest fractional anisotropy in the same tract at 6 months of age. This is one of the first studies to report significant associations between caregiver speech collected in the home and white matter structural coherence in the infant brain. The results are in line with prior work showing that protracted white matter development during infancy confers a cognitive advantage.

Variable patterns of daily activity participation across settings in autistic youth: A latent profile transition analysis.

LAY ABSTRACT: What people do or engage in in their daily lives, or daily life participation, is often linked to their state of being happy and healthy, as well as potential for living independently. To date, little research has been conducted on daily activity participation by autistic youth at home, at school or in the community. Learning more about individual differences in participation levels and what might influence them can help to create custom supports for autistic youth and their families. In this study, 158 caregivers of autistic youth were asked how often their children took part in 25 common activities at two assessments, about one year apart. The analysis showed three profiles for each of the home and school settings and two profiles for the community setting. These profiles reflected distinct patterns in how often autistic youth took part in various daily activities, particularly in doing homework, school club activities and community gatherings. Most autistic youth were in profiles marked by often taking part at home but less often at school and in the community, and about three-fourths of them tended to stay in the same profile over time. Autistic youth with limited participation profiles were more likely to have lower scores on measures of cognitive ability and daily life skills and more challenging behaviour, and faced more barriers in their environment. These findings show how important it is to think about each autistic person's strengths and weaknesses, and changing needs, to better support their daily life participation.

Longitudinal associations between early childhood irritability and adolescent depression symptoms in autistic children are mediated by peer relationships but not educational engagement.

In the general population, irritability is associated with later depression. Despite irritability being more prevalent in autistic children, the long-term sequelae are not well explored. We tested whether irritability in early childhood predicted depression symptoms in autistic adolescents, and whether associations could be explained by difficulties in peer relationships and lower educational engagement. Analyses tested the longitudinal associations between early childhood irritability (ages 3-5) and adolescent depression symptoms (age 14) in a prospective inception cohort of autistic children (N = 390), followed from early in development shortly after they received a clinical diagnosis. Mediators were measured in mid-childhood (age 10) by a combination of measures, from which latent factors for peer relationships and educational engagement were estimated. Results showed early childhood irritability was positively associated with adolescent depression symptoms, and this association remained when adjusting for baseline depression. A significant indirect pathway through peer relationships was found, which accounted for around 13% of the association between early childhood irritability and adolescent depression, suggesting peer problems may partially mediate the association between irritability and later depression. No mediation effects were found for education engagement. Results highlight the importance of early screening and intervention for co-occurring irritability and peer problems in young autistic children.

A Prospective Evaluation of Infant Cerebellar-Cerebral Functional Connectivity in Relation to Behavioral Development in Autism Spectrum Disorder.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder diagnosed based on social impairment, restricted interests, and repetitive behaviors. Contemporary theories posit that cerebellar pathology contributes causally to ASD by disrupting error-based learning (EBL) during infancy. The present study represents the first test of this theory in a prospective infant sample, with potential implications for ASD detection. Methods: Data from the Infant Brain Imaging Study (n = 94, 68 male) were used to examine 6-month cerebellar functional connectivity magnetic resonance imaging in relation to later (12/24-month) ASD-associated behaviors and outcomes. Hypothesis-driven univariate analyses and machine learning-based predictive tests examined cerebellar-frontoparietal network (FPN; subserves error signaling in support of EBL) and cerebellar-default mode network (DMN; broadly implicated in ASD) connections. Cerebellar-FPN functional connectivity was used as a proxy for EBL, and cerebellar-DMN functional connectivity provided a comparative foil. Data-driven functional connectivity magnetic resonance imaging enrichment examined brain-wide behavioral associations, with post hoc tests of cerebellar connections. Results: Cerebellar-FPN and cerebellar-DMN connections did not demonstrate associations with ASD. Functional connectivity magnetic resonance imaging enrichment identified 6-month correlates of later ASD-associated behaviors in networks of a priori interest (FPN, DMN), as well as in cingulo-opercular (also implicated in error signaling) and medial visual networks. Post hoc tests did not suggest a role for cerebellar connections. Conclusions: We failed to identify cerebellar functional connectivity-based contributions to ASD. However, we observed prospective correlates of ASD-associated behaviors in networks that support EBL. Future studies may replicate and extend network-level positive results, and tests of the cerebellum may investigate brain-behavior associations at different developmental stages and/or using different neuroimaging modalities.

Brief Report: Plasma Leptin and Mealtime Feeding Behaviors Among Children with Autism Spectrum Disorder: A Pilot Study.

We examined the relationship between weight status, appetite regulating hormones, and mealtime behaviors among children, (5-12 years old), diagnosed with Autism Spectrum Disorder (ASD) in a cross-sectional study. All (N = 21) completed anthropometry measurements and (n = 18) provided blood samples for hormone analysis. Mealtime behavior, dietary, physical activity, puberty stage, and social impairment data were collected. Under fasting conditions, overweight/obese (OWOB) participants, (n = 6), had higher leptin concentrations (p < 0.02) and more feeding challenges (p < 0.05) than normal weight (n = 15). Higher leptin levels and disruptions in mealtime behaviors may exist among OWOB children in this study. Future longitudinal studies that examine appetite regulating hormones and mealtime behaviors may inform our understanding of the role of these markers in the development of obesity in ASD.

Examining clinical characteristics of autism and links with parent perceptions of sibling relationship quality.

LAY ABSTRACT: Sibling relationship quality is important for the well-being of children on the autism spectrum and their siblings. Little is known, however, about how varied behavior and abilities of children on the autism spectrum may be associated with parent perceptions of domains of sibling relationship quality. We drew data from a subsample of 119 children on the autism spectrum (ages 10-11 years), participating in an ongoing longitudinal study. We looked at how three clinical characteristics (autism symptoms, behavioral difficulties, and communication ability) related to four areas of parent-reported sibling relationship quality (warmth/closeness, conflict, relative status/power, and rivalry). We also examined whether the strength of the association between behavioral difficulties and parent-reported sibling relationship quality was influenced by communication ability. We found that more severe autism symptoms were associated with less conflict and rivalry, and higher communication ability was associated with more relative status/power. We also found that children on the autism spectrum with more behavioral difficulties and weaker communication ability had less warmth/closeness in their sibling relationships. Our findings highlight that it is important to consider autism symptoms, behavioral difficulties, and communication ability, as well as multiple domains of relationship quality, to better understand how parents view the relationships between autistic children and their siblings. Clinically, methods for improving sibling relationships may include teaching conflict resolution strategies to children on the autism spectrum with stronger communication abilities and their siblings, and fostering sibling connection for those with lower communication abilities.

Construct Validity of the Autism Classification System of Functioning: Social Communication (ACSF:SC) Across Childhood and Adolescence.

This study examined the construct validity of the Autism Classification System of Functioning: Social Communication (ACSF). Participants included 145 parents of children with autism (2-19 years). The degree of convergent and discriminant validity between parent reported ACSF and subscales from Social Responsiveness Scale 2nd edition and Behavior Assessment System for Children, 3rd Edition were examined against a priori hypotheses. We examined construct validity in the entire sample as well as in specific age cohorts. Our findings suggest that ACSF can provide a valid classification system of social communication ability in children with autism 2-19 years of age, and its two subscales may be used to examine different aspects of social communication ability.

Developmental cascades between insistence on sameness behaviour and anxiety symptoms in autism spectrum disorder.

Autistic children experience high rates of anxiety. Insistence on sameness behaviour (IS) is a core feature of autism that appears correlated with anxiety severity. The objective of this study was to examine the longitudinal relations between anxiety and IS in autistic children using a developmental cascade model. A longitudinal cohort of 421 autistic children was followed between 4 and 11 years of age. Anxiety was quantified using items from the Anxiety Problems subscale of the Child Behavior Checklist; sameness behaviours were measured using the Repetitive Behavior Scale-Revised, Ritualistic/sameness subscale (both parent-report measures). Structural equation modelling was used to examine the longitudinal and directional associations between anxiety and IS at four time-points, through cross-lagged panel models (CLPM) with and without a random-intercepts component (RI-CLPM). Both the CLPM and the RI-CLPM had good fit. Significant directional associations were detected whereby elevated or increasing IS preceded elevated or increasing anxiety symptoms 1-2 years later, respectively. Stable baseline tendencies towards anxiety and IS as between-person traits (intercepts) were strongly associated (standardized estimate = 0.69, p < 0.001). The magnitude of the cross-sectional associations between anxiety and IS appeared to lessen with age. IS and anxiety symptoms in autism are closely related. They appear to be shared traits that mirror each other particularly in younger children. Increasing IS may be a sign of emerging future anxiety. Interventions that target IS to reduce or prevent anxiety amongst school-aged autistic children merit further study.