Systematic comparisons of different quality control approaches applied to three large pediatric neuroimaging datasets.

INTRODUCTION: Poor quality T1-weighted brain scans systematically affect the calculation of brain measures. Removing the influence of such scans requires identifying and excluding scans with noise and artefacts through a quality control (QC) procedure. While QC is critical for brain imaging analyses, it is not yet clear whether different QC approaches lead to the exclusion of the same participants. Further, the removal of poor-quality scans may unintentionally introduce a sampling bias by excluding the subset of participants who are younger and/or feature greater clinical impairment. This study had two aims: (1) examine whether different QC approaches applied to T1-weighted scans would exclude the same participants, and (2) examine how exclusion of poor-quality scans impacts specific demographic, clinical and brain measure characteristics between excluded and included participants in three large pediatric neuroimaging samples. METHODS: We used T1-weighted, resting-state fMRI, demographic and clinical data from the Province of Ontario Neurodevelopmental Disorders network (Aim 1: n = 553, Aim 2: n = 465), the Healthy Brain Network (Aim 1: n = 1051, Aim 2: n = 558), and the Philadelphia Neurodevelopmental Cohort (Aim 1: n = 1087; Aim 2: n = 619). Four different QC approaches were applied to T1-weighted MRI (visual QC, metric QC, automated QC, fMRI-derived QC). We used tetrachoric correlation and inter-rater reliability analyses to examine whether different QC approaches excluded the same participants. We examined differences in age, mental health symptoms, everyday/adaptive functioning, IQ and structural MRI-derived brain indices between participants that were included versus excluded following each QC approach. RESULTS: Dataset-specific findings revealed mixed results with respect to overlap of QC exclusion. However, in POND and HBN, we found a moderate level of overlap between visual and automated QC approaches (rtet=0.52-0.59). Implementation of QC excluded younger participants, and tended to exclude those with lower IQ, and lower everyday/adaptive functioning scores across several approaches in a dataset-specific manner. Across nearly all datasets and QC approaches examined, excluded participants had lower estimates of cortical thickness and subcortical volume, but this effect did not differ by QC approach. CONCLUSION: The results of this study provide insight into the influence of QC decisions on structural pediatric imaging analyses. While different QC approaches exclude different subsets of participants, the variation of influence of different QC approaches on clinical and brain metrics is minimal in large datasets. Overall, implementation of QC tends to exclude participants who are younger, and those who have more cognitive and functional impairment. Given that automated QC is standardized and can reduce between-study differences, the results of this study support the potential to use automated QC for large pediatric neuroimaging datasets.

Disentangling global and domain-level adaptive behavior trajectories among children with autism spectrum disorder.

BACKGROUND: Heterogeneity in adaptive behavior abilities among people with autism spectrum disorder (ASD) is expressed not only as uneven levels of impairment across domains, but also in the developmental trajectories of adaptive skills. We studied the question of whether, after accounting for global adaptive behavior development, we find evidence of heterogeneity in the trajectories of specific domains of adaptive behavior. METHODS: A sample of 504 children with ASD was obtained by combining data from two independent natural history studies conducted in North America. We used a factor of curves model to explain growth between 36 and 138 months in Vineland Adaptive Behavior Scales, Second Edition (VABS) age equivalents as a function of domain-specific and global growth processes. RESULTS: The domain-specific trajectories in all three domains (Communication, Daily Living Skills, and Socialization) reflected impairment relative to age expectations as well as slower-than-expected growth with age, and the parameters of these trajectories were moderately-to-strongly correlated across domains. The global adaptive behavior trajectory had an initial (36-41 months of age) developmental level of about 22 age-equivalent months, and eventually slowed after initially increasing by about 6 months each year. The global trajectory accounted for the majority of variance in the domain-level processes; however, additional variance remained (14%-38%) in the domain-level intercepts, slopes, and quadratic processes. CONCLUSIONS: These results extend existing theoretical and empirical support for the hierarchical structure of adaptive behavior to include its development over time in clinical samples of children with ASD. A latent global trajectory may be sufficient to describe the growth of adaptive behavior in children with ASD; however, the remaining domain-specific variability after accounting for global adaptive behavior development allows for the possibility that differential effects of intervention on specific domains may be possible and detectable.

Cortical Gyrification Morphology in ASD and ADHD: Implication for Further Similarities or Disorder-Specific Features?

Shared etiological pathways are suggested in ASD and ADHD given high rates of comorbidity, phenotypic overlap and shared genetic susceptibility. Given the peak of cortical gyrification expansion and emergence of ASD and ADHD symptomology in early development, we investigated gyrification morphology in 539 children and adolescents (6-17 years of age) with ASD (n=197) and ADHD (n=96) compared to typically developing controls (n=246) using the local Gyrification Index (lGI) to provide insight into contributing etiopathological factors in these two disorders. We also examined IQ effects and functional implications of gyrification by exploring the relation between lGI and ASD and ADHD symptomatology beyond diagnosis. General Linear Models yielded no group differences in lGI, and across groups, we identified an age-related decrease of lGI and greater lGI in females compared to males. No diagnosis-by-age interactions were found. Accounting for IQ variability in the model (n=484) yielded similar results. No significant associations were found between lGI and social communication deficits, repetitive and restricted behaviours, inattention or adaptive functioning. By examining both disorders and controls using shared methodology, we found no evidence of atypicality in gyrification as measured by the lGI in these conditions.

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.

Population-Based Teacher-Rated Assessment of Anxiety Among Canadian Kindergarten Children.

Despite anxiety being a prevalent mental health problem in children, little data exist on the pervasiveness and levels of anxiety symptoms in kindergarteners. Data from the Early Development Instrument, a teacher-completed, population-level measure of child development, were collected across Canada from 2004 to 2015. The final analytic sample consisted of 974,319 children of whom 2.6% were classified as "highly anxious". Compared to children who exhibited "few to none" anxious behaviors, highly anxious children were more likely to be male, have English/French as a second language, and have a special needs designation. Furthermore, compared with their less anxious peers, highly anxious children had between 3.5 and 6.1 higher odds of scoring below the 10th percentile cut-off in physical, social, language/cognitive and communication domains. Our findings suggest that anxious behaviors are related to children's overall health and illustrate the consistency and extensiveness of anxiety at a very young age among Canadian children.

Amygdala subnuclei volumes and anxiety behaviors in children and adolescents with autism spectrum disorder, attention deficit hyperactivity disorder, and obsessive-compulsive disorder.

Alterations in the structural maturation of the amygdala subnuclei volumes are associated with anxiety behaviors in adults and children with neurodevelopmental and associated disorders. This study investigated the relationship between amygdala subnuclei volumes and anxiety in 233 children and adolescents (mean age = 11.02 years; standard deviation = 3.17) with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and children with obsessive compulsive disorder (OCD), as well as typically developing (TD) children. Parents completed the Child Behavior Checklist (CBCL), and the children underwent structural MRI at 3 T. FreeSurfer software was used to automatically segment the amygdala subnuclei. A general linear model revealed that children and adolescents with ASD, ADHD, and OCD had higher anxiety scores compared to TD children (p < .001). A subsequent interaction analysis revealed that children with ASD (B = 0.09, p < .0001) and children with OCD (B = 0.1, p < .0001) who had high anxiety had larger right central nuclei volumes compared with TD children. Similar results were obtained for the right anterior amygdaloid area. Amygdala subnuclei volumes may be key to identifying children with neurodevelopmental disorders or those with OCD who are at high risk for anxiety. Findings may inform the development of targeted behavioral interventions to address anxiety behaviors and to assess the downstream effects of such interventions.

Obsessive-compulsive disorder in children and youth: neurocognitive function in clinic and community samples.

BACKGROUND: Neurocognitive impairments are common in OCD, although not well studied in children and youth with the disorder. METHOD: Using the stop-signal task (SST), we measured response inhibition (stop-signal reaction time-SSRT), sustained attention (reaction time variability-RTV), reaction time (RT), and performance monitoring (post-error slowing-PES) in OCD cases and controls from two samples of children and youth. A Clinic OCD group (n = 171, aged 7-17 years) was recruited from a specialty clinic after rigorous assessment. A typically developing (Clinic TD, n = 157) group was enlisted through advertisement. A community OCD sample (Community OCD, n = 147) and controls (Community TD n = 13,832, aged 6-17 years) were recruited at a science museum. We also identified a community group with high OCD traits without an OCD diagnosis (Community High Trait; n = 125). RESULTS: Clinic OCD participants had longer SSRT and greater RTV than Clinic TD. These effects were greater in younger OCD participants and, for SSRT, in those on medication for OCD. The Community OCD group did not differ from Controls but was similar to the Clinic OCD group in ADHD and ASD comorbidity and medication usage. The Community High Trait group had longer SSRT and atypical PES suggesting that symptom severity predicts neurocognitive function. No group differences were found in RT. CONCLUSIONS: In the largest study of neurocognitive performance in children with OCD to date, we found impaired response inhibition and sustained attention in OCD participants in comparison to typically developing peers. Performance was worse in younger OCD participants. In the community sample, participants with high OCD trait scores but no OCD diagnosis had impaired response inhibition and error processing, suggesting that OCD might be under-recognized.

Characterizing the ASD-ADHD phenotype: measurement structure and invariance in a clinical sample.

BACKGROUND: Autism Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) have considerable overlap, supporting the need for a dimensional framework that examines neurodevelopmental domains which cross traditional diagnostic boundaries. In the following study, we use factor analysis to deconstruct the ASD-ADHD phenotype into its underlying phenotypic domains and test for measurement invariance across adaptive functioning, age, gender and ASD/ADHD clinical diagnoses. METHODS: Participants included children and youth (aged 3-20 years) with a clinical diagnosis of ASD (n = 727) or ADHD (n = 770) for a total of 1,497 participants. Parents of these children completed the Social Communication Questionnaire (SCQ), a measure of autism symptoms, and the Strengths and Weaknesses of ADHD and Normal Behaviour (SWAN) questionnaire, a measure of ADHD symptoms. An exploratory factor analysis (EFA) was performed on combined SCQ and SWAN items. This was followed by a confirmatory factor analysis (CFA) and tests of measurement invariance. RESULTS: EFA revealed a four-factor solution (inattention, hyperactivity/impulsivity, social-communication, and restricted, repetitive, behaviours and interests (RRBI)) and a CFA confirmed good model fit. This solution also showed good model fit across subgroups of interest. CONCLUSIONS: Our study shows that a combined ASD-ADHD phenotype is characterized by two latent ASD domains (social communication and RRBIs) and two latent ADHD domains (inattention and hyperactivity/impulsivity). We established measurement invariance of the derived measurement model across adaptive functioning, age, gender and ASD/ADHD diagnoses.

Predictors of language regression and its association with subsequent communication development in children with autism.

BACKGROUND: Language regression, broadly defined as the loss of acquired language skills in early childhood, is a distinctive feature of autism. Little is known about the factors underlying regression or the prognosis of children who exhibit regression. We examine potential predictors of language regression and test its association with language development in a prospective longitudinal sample of children with autism spectrum disorder (ASD) from diagnosis to age 10 years. METHODS: We analysed data from Pathways in ASD, a prospective longitudinal study of 421 children enrolled around the time of an autism diagnosis between 2 and 5 years. Autism Diagnostic Interview-Revised data were available for 408 children, of whom 90 (22%) were classified as having language regression. RESULTS: Demographic and other health factors including caregiver education, family income, child sex, reported seizures, and age of enrolment did not differ between children with and without language regression. Children with language regression walked earlier and attained first words sooner than those without regression. However, both groups attained phrase speech at comparable ages. Those with regression exhibited greater delays in expressive and receptive communication over the follow-up period, although this effect was attenuated when accounting for baseline differences in motor and cognitive ability. Overall, those with language regression continued to exhibit expressive but not receptive communication delay compared to those without regression. Communication trajectories were heterogeneous to age 10 years, irrespective of regression status. CONCLUSIONS: Although language regression can be alarming, our findings confirm that its occurrence does not necessarily foreshadow worse developmental outcomes relative to those without regression. Although a discrepancy in age-equivalent communication skills may persist, this can be expected to be of less practical importance with rising average levels of skills. Future studies need to account for the significant variability in language trajectories by considering factors beyond developmental regression.

Middle-childhood executive functioning mediates associations between early-childhood autism symptoms and adolescent mental health, academic and functional outcomes in autistic children.

BACKGROUND: Executive functioning (EF) varies in children with autism spectrum disorder (ASD) and is associated with clinical symptoms, academic, and adaptive functioning. Here, we examined whether middle-childhood EF mediates associations between early-childhood autism symptoms and adolescent outcomes in children with ASD. METHODS: The Pathways in ASD Cohort comprising children recruited at the time of ASD diagnosis (at 2-4 years-of-age) and followed prospectively across eight subsequent timepoints over ~10 years was used. A subset of Pathways participants (n = 250) with Behavior Rating Inventory of Executive Function (BRIEF)-Parent Form data from at least one timepoint when participants were school-aged was analyzed. A mediation framework was used to examine whether BRIEF-measured EF across age 7-10 years (middle-childhood) mediated associations between early-childhood autism symptoms (measured using the parent-report Social Responsiveness Scale across age 2-6 years) and clinical, academic, and functional outcomes, indexed at age >10-11.8 years (early-adolescence) using the Child Behavior Checklist (CBCL)-Internalizing and Externalizing Scales, Academic Performance from the Teacher's Report Form, and Vineland Adaptive Behavior Scales. Models were rerun substituting clinician-rated and teacher-rated measures, where possible. RESULTS: Mediation models indicated a significant indirect effect of middle-childhood EF on associations between early-childhood autism symptoms and externalizing behavior, academic performance, or adaptive functioning in early adolescence; kappa squared (κ2 ) effect sizes ranged from large to small. Model findings were stable across raters. Middle-childhood EF did not mediate associations between early-childhood autism symptoms and adolescent internalizing behavior. CONCLUSIONS: Among children with an ASD diagnosis, middle-childhood EF may be one pathway through which early-childhood autism symptoms influence a variety of outcomes in early-adolescence. An experimental study targeting middle-childhood EF to improve adolescent academic, emotional/behavioral, and adaptive functioning is needed to evaluate the clinical meaningfulness of these findings.

Cross-Diagnosis Structural Correlates of Autistic-Like Social Communication Differences.

Social communication differences are seen in autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and obsessive-compulsive disorder (OCD), but the brain mechanisms contributing to these differences remain largely unknown. To address this gap, we used a data-driven and diagnosis-agnostic approach to discover brain correlates of social communication differences in ASD, ADHD, and OCD, and subgroups of individuals who share similar patterns of brain-behavior associations. A machine learning pipeline (regression clustering) was used to discover the pattern of association between structural brain measures (volume, surface area, and cortical thickness) and social communication abilities. Participants (n = 416) included children with a diagnosis of ASD (n = 192, age = 12.0[5.6], 19% female), ADHD (n = 109, age = 11.1[4.1], 18% female), or OCD (n = 50, age = 12.3[4.2], 42% female), and typically developing controls (n = 65, age = 11.6[7.1], 48% female). The analyses revealed (1) associations with social communication abilities in distributed cortical and subcortical networks implicated in social behaviors, language, attention, memory, and executive functions, and (2) three data-driven, diagnosis-agnostic subgroups based on the patterns of association in the above networks. Our results suggest that different brain networks may contribute to social communication differences in subgroups that are not diagnosis-specific.

Program evaluation of a pilot mobile developmental outreach clinic for autism spectrum disorder in Ontario.

BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopmental disorder with increasing prevalence worldwide. Early identification of ASD through developmental screening is critical for early intervention and improved behavioural outcomes in children. However due to long wait times, delays in diagnosis continue to occur, particularly among minority populations who are faced with existing barriers in access to care. A novel Mobile Developmental Outreach Clinic (M-DOC) was implemented to deliver culturally sensitive screening and assessment practices to increase access to developmental health services, reduce wait times in diagnoses, and aid in equitable access to intervention programs among vulnerable populations in Ontario. METHODS: This study applied two evaluation frameworks (process and outcome evaluation) to determine whether the delivery model was implemented as intended, and if the program achieved its targeted goals. A mixed-methods design was undertaken to address the study objectives. RESULTS: Between September 2018-February 2020, M-DOC reached 227 families with developmental health concerns for their child, while successfully targeting the intended population and achieving its goals. The mean age of the child-in-need at intake was 31.6 months (SD 9.9), and 70% of the sample were male. The program's success was attributed to the use of cultural liaisons to break cultural and linguistic barriers, the creation of multiple points of access into the diagnosis pathway, and delivery of educational workshops in local communities to raise awareness and knowledge of autism spectrum disorder. CONCLUSIONS: The findings underscore the need for community-based intervention programs that focus on cultural barriers to accessing health services. The model of delivery of the M-DOC programs highlights the opportunity for other programs to adopt a similar mobile outreach clinic approach as a means to increase access to services, particularly in targeting hard-to-reach and vulnerable populations.

Mental health profiles of autistic children and youth during the COVID-19 pandemic.

Objectives: Canadian province-wide lockdowns have challenged children's mental health (MH) during the COVID-19 pandemic, with autistic children being at particular risk. The purpose of our study was to identify sub-groups of autistic children with distinct mental health change profiles, to understand the child-, parent-, and system-specific factors associated with such profiles in order to ultimately inform future interventions. Methods: Data were drawn from a large Canadian cohort (N=1,570) across Ontario, resulting in 265 autistic children (mean age=10.9 years, 76% male). K-means clustering analyses were employed to partition distinct MH profiles in six MH measures (mood, anxiety, OCD symptoms, irritability, inattention, hyperactivity) and group differences were examined with reference to the above factors. Additionally, we investigated the characteristics of children who accessed acute MH services. Results: The optimal number of clusters was two; one included those experiencing MH deterioration across all six MH measures (61.3%, 95% confidence interval [CI]=54.9 to 67.4), and a second included youth that did not experience MH changes (38.7%, 95%CI=32.6 to 45.1). Child-specific factors associated with MH deterioration included higher pre-existing internalizing symptoms, high levels of COVID stress. Parental MH challenges and system-specific factors, such as the loss of learning supports, access to physicians and material deprivation, were also associated with MH deterioration. Access to acute MH services were primarily associated with financial insecurity and loss of services. Conclusions: More than half of autistic children experienced MH deterioration, and person-specific (pre-existing MH, COVID related stress), parent-specific (Parent MH) and system-level (loss of services and material deprivation) characteristics were associated with such decline, providing clinical and policy opportunities for intervention at multiple levels.

Co-occurring trajectories of anxiety and insistence on sameness behaviour in autism spectrum disorder.

BACKGROUND: Children with autism spectrum disorder (ASD) have increased susceptibility to anxiety disorders. Variation in a common ASD symptom, insistence on sameness behaviour, may predict future anxiety symptoms. AIMS: To describe the joint heterogeneous longitudinal trajectories of insistence on sameness and anxiety in children with ASD and to characterise subgroups at higher risk for anxiety. METHOD: In a longitudinal ASD cohort (n = 421), insistence on sameness behaviour was measured using the Autism Diagnostic Interview-Revised at approximately ages 3, 6 and 11 years. Anxiety was quantified at 8 time points between ages 3 and 11 years using the Child Behavior Checklist (CBCL) (parent report). Clusters of participants following similar trajectories were identified using group-based and joint trajectory modelling. RESULTS: Three insistence on sameness trajectories were identified: (a) 'low-stable' (41.7% of participants), (b) 'moderate-increasing' (52.0%) and (c) 'high-peaking' (i.e. increasing then stabilising/decreasing behaviour) (6.3%). Four anxiety trajectories were identified: (a) 'low-increasing' (51.0%), (b) 'moderate-decreasing' (16.2%), (c) 'moderate-increasing' (19.6%) and (d) 'high-stable' (13.1%). Of those assigned to the 'high-peaking' insistence on sameness trajectory, 95% jointly followed an anxiety trajectory that surpassed the threshold for clinical concern (T-score >65) by middle childhood (anxiety trajectories 3 or 4). Insistence on sameness and anxiety trajectories were similar in severity and direction for 64% of the sample; for 36%, incongruous patterns were seen (e.g. decreasing anxiety and increasing insistence on sameness). CONCLUSIONS: The concurrent assessment of insistence on sameness behaviour and anxiety in ASD may help in understanding current symptom profiles and anticipating future trajectories. High preschool insistence on sameness in particular may be associated with elevated current or future anxiety symptoms.

Sex differences in scores on standardized measures of autism symptoms: a multisite integrative data analysis.

BACKGROUND: Concerns have been raised that scores on standard measures of autism spectrum disorder (ASD) symptoms may differ as a function of sex. However, these findings are hindered by small female samples studied thus far. The current study evaluated if, after accounting for age, IQ, and language level, sex affects ASD severity estimates from diagnostic measures among children with ASD. METHODS: Data were obtained from eight sources comprising 27 sites. Linear mixed-effects models, including a random effect for site, were fit for 10 outcomes (Autism Diagnostic Observation Schedule [ADOS] domain-level calibrated severity scores, Autism Diagnostic Interview-Revised [ADI-R] raw scores by age-based algorithm, and raw scores from the two indices on the Social Responsiveness Scale [SRS]). Sex was added to the models after controlling for age, NVIQ, and an indicator for language level. RESULTS: Sex significantly improved model fit for half of the outcomes, but least square mean differences were generally negligible (effect sizes [ES] < 0.20), increasing to small to moderate in adolescence (ES < 0.40). Boys received more severe RRB scores than girls on both the ADOS and ADI-R (age 4 + algorithm), and girls received more severe scores than boys on both SRS indices, which emerged in adolescence. CONCLUSIONS: This study combined several available databases to create the largest sample of girls with ASD diagnoses. We found minimal differences due to sex beyond other known influences on ASD severity indicators. This may suggest that, among children who ultimately receive a clinical ASD diagnosis, severity estimates do not systematically differ to such an extent that sex-specific scoring procedures would be necessary. However, given the limitations inherent in clinically ascertained samples, future research must address questions about systematic sex differences among children or adults who do not receive clinical diagnoses of ASD. Moreover, while the current study helps resolve questions about widely used diagnostic instruments, we could not address sex differences in phenotypic aspects outside of these scores.

Profiles and Predictors of Academic and Social School Functioning among Children with Autism Spectrum Disorder.

Objective: The purpose of the study was to identify profiles and predictors of academic and social functioning in a sample of school-age children with autism spectrum disorder.Method: The study included 178 children (88% boys, 75% Caucasian, ages 10-11) who completed a standardized measure of academic skills and whose teachers completed a related measure. Measures of both academic and social performance were used to construct profiles of school functioning. Measures of language, nonverbal IQ, autism symptom severity, behavior difficulties, and early social-communication skills between ages 3 and 4 were used to examine predictors of profile membership. Latent Profile Analysis was used to identify and describe profiles of children's academic and social school functioning. Profile membership was then regressed on each of the predictors using a series of multinomial logistic regression models. Finally, a multivariate model that included all significant predictors was built to examine the best fitting constellation of profile predictors.Results: Four profiles - reflecting variation in academic achievement, school engagement, socialization skills, pragmatic language use, and social relationships - captured the diverse school functioning outcomes of the sample. Profile membership was predicted by variation in imitation, responding to joint attention, language ability, nonverbal IQ and behavior difficulties between ages 3 and 4 years. However, in a multivariate model, only language and behavior difficulties emerged as significant predictors.Conclusions: A person-centered approach to targeted early intervention that reduces behavior difficulties and enhances social-communication and language abilities may prove especially important for the promotion of later academic and social functioning at school.

Sex Differences in Age of Diagnosis and First Concern among Children with Autism Spectrum Disorder.

OBJECTIVE: Early identification of autism spectrum disorder (ASD) is an essential healthcare priority. Girls may be at risk for late diagnosis, although research is equivocal regarding how sex and other factors relate to ASD identification. The goals of the current investigation were to (1) identify how child sex, cognitive abilities, and demographic factors relate to age of first concern (AOC) and age of diagnosis (AOD), (2) evaluate trends in AOC/AOD over time, and (3) consider whether main effects of sex on AOC/AOD are moderated by cognitive abilities or time. METHOD: Children (N = 365; 20% female; 85.6% identified as White) with ASD participated through the Province of Ontario Neurodevelopmental Disorders (POND) Network. Study records included AOD, date/timing of diagnosis (between 1996 and 2017), age of first parent concern, demographics, and standardized cognitive testing results (24.7% of children had IQ scores below standard scores of 70). RESULTS: Average AOC occurred before 2 years of age whereas average AOD occurred after 5 years of age. Girls did not differ on AOC but had a later AOD than boys. Higher verbal IQ was associated with later AOD more strongly in girls than boys. Regarding time-related changes, average AOC and AOD increased across the study period, more strongly for girls. CONCLUSIONS: Results support that sex is a key factor underlying delays in ASD identification and highlight the urgent need to improve diagnostic practices among girls. Limitations and implications for improving the diagnostic process are discussed.Abbreviations: ASD=autism spectrum disorder; IQ=intelligence quotient; AOC=parental report of age of first concern; AOD=age of diagnosis.

Predictors of longer-term development of expressive language in two independent longitudinal cohorts of language-delayed preschoolers with Autism Spectrum Disorder.

BACKGROUND: Studies estimate that 30% of individuals with autism are minimally verbal. Understanding what factors predict longer-term expressive development in children with language delays is critical to inform identification and treatment of those at-risk for persistent language impairments. The present study examined predictors of expressive language development in language-delayed preschoolers followed through later school-age and young adulthood. METHODS: Children using single words or less on the Autism Diagnostic Observation Schedule (ADOS) at approximately 3 years old were drawn from the Early Diagnosis (EDX) and Pathways in ASD longitudinal cohorts. Age-3 predictors of Age-19 ADOS language level were identified using Classification and Regression Trees (CART) in the EDX sample. Linear mixed models examined the effects of CART-identified predictors on Vineland expressive communication (VExp) trajectories from Age-3 to Age-19. The same linear mixed models were examined in the Pathways sample, identifying predictors of VExp from ages 3 to 10.5 years. RESULTS: Significantly delayed fine motor skills (T-score < 20) was the strongest CART predictor of Age-19 language. In the linear mixed models, time, Age-3 fine motor skills and initiation of joint attention (IJA) predicted VExp trajectories in the EDX sample, even when controlling for Age-3 visual receptive abilities. In the Pathways sample, time and Age-3 fine motor skills were significant predictors of VExp trajectories; IJA and cognitive skills were not significant predictors. CONCLUSIONS: Marked deficits in fine motor skills may be a salient proxy marker for identifying language-delayed children with ASD who are at risk for persistent language impairments. This finding adds to the literature demonstrating a relation between motor and language development in ASD. Investigating individual skill areas (e.g., fine motor and nonverbal problem-solving skills), rather than broader indices of developmental level (e.g., nonverbal IQ) may provide important cues to understanding longer-term language outcomes that can be targeted in early intervention.

Developmental Trajectories of Feeding Problems in Children with Autism Spectrum Disorder.

OBJECTIVE: Although feeding problems are a common concern in children with autism spectrum disorder (ASD), few longitudinal studies have examined their persistence over time. The purpose of this study was to examine the developmental progression of feeding problems across four time points in preschoolers with ASD. METHODS: Group-based trajectory analyses revealed four distinct trajectories of feeding problems in our sample (N = 396). RESULTS: The majority of children showed levels of feeding problems that were low from the outset and stable (Group 1; 26.3%) or moderate and declining over time (Group 2; 38.9%). A third group (26.5%) showed high levels of feeding problems as preschoolers that declined to the average range by school age. Few participants (8.3%) showed evidence of severe chronic feeding problems. Feeding problems were more highly correlated with general behavior problems than with autism symptom severity. CONCLUSIONS: Overall, our findings demonstrated that in our sample of children with ASD, most feeding problems remitted over time, but a small subgroup showed chronic feeding problems into school age. It is important to consider and assess feeding problems in ASD against the backdrop of typical development, as many children with ASD may show improvement with age.

Developmental functioning and symptom severity influence age of diagnosis in Canadian preschool children with autism.

BACKGROUND: Early diagnosis of autism spectrum disorder (ASD) is essential in most Canadian jurisdictions to access interventions that improve long-term child outcomes. Our main objective was to identify factors associated with timing of ASD diagnosis in five provinces across Canada. METHODS: Factors influencing age of diagnosis were assessed in the analyses of an inception cohort of children diagnosed with ASD between ages 2 and 5 years. We examined bivariate associations and using a series of multiple variable regression models, evaluated the unique contributions of developmental functioning, ASD symptoms and demographic variables. Children with known genetic abnormalities, or severe sensory or motor impairments interfering with assessment were excluded. RESULTS: Participants were 421 children (84.6% boys). The mean age of diagnosis was 38.2 months (SD=8.7), an average of 19 months after parents identified initial concerns. Factors associated with later diagnosis included more advanced language and cognitive skills, and higher levels of restricted repetitive behaviour symptoms. Child sex and family demographics were not associated with age of diagnosis. In regression analyses, language and cognitive skills accounted for 6.8% of variance in age of diagnosis and ASD symptoms contributed an additional 5.5%. Provincial site accounted for 4.0% of variance in age of diagnosis, independent of developmental skills and ASD symptoms. INTERPRETATION: Diagnosis of ASD occurred, on average, 19 months after parents' initial concerns. Language and cognitive skills, symptom severity and provincial site accounted for variation in age of ASD diagnosis in this Canadian cohort. Variable presentation across the developmental continuum must be considered in planning assessment services to ensure timely ASD diagnosis so that outcomes can be improved. Policy and practice leadership is also needed to reduce interprovincial variability.