Development of webcam-collected and artificial-intelligence-derived social and cognitive performance measures for neurodevelopmental genetic syndromes.

This study focused on the development and initial psychometric evaluation of a set of online, webcam-collected, and artificial intelligence-derived patient performance measures for neurodevelopmental genetic syndromes (NDGS). Initial testing and qualitative input was used to develop four stimulus paradigms capturing social and cognitive processes, including social attention, receptive vocabulary, processing speed, and single-word reading. The paradigms were administered to a sample of 375 participants, including 163 with NDGS, 56 with idiopathic neurodevelopmental disability (NDD), and 156 neurotypical controls. Twelve measures were created from the four stimulus paradigms. Valid completion rates varied from 87 to 100% across measures, with lower but adequate completion rates in participants with intellectual disability. Adequate to excellent internal consistency reliability (α = 0.67 to 0.95) was observed across measures. Test-retest reproducibility at 1-month follow-up and stability at 4-month follow-up was fair to good (r = 0.40-0.73) for 8 of the 12 measures. All gaze-based measures showed evidence of convergent and discriminant validity with parent-report measures of other cognitive and behavioral constructs. Comparisons across NDGS groups revealed distinct patterns of social and cognitive functioning, including people with PTEN mutations showing a less impaired overall pattern and people with SYNGAP1 mutations showing more attentional, processing speed, and social processing difficulties relative to people with NFIX mutations. Webcam-collected performance measures appear to be a reliable and potentially useful method for objective characterization and monitoring of social and cognitive processes in NDGS and idiopathic NDD. Additional validation work, including more detailed convergent and discriminant validity analyses and examination of sensitivity to change, is needed to replicate and extend these observations.

Development of informant-report neurobehavioral survey scales for PTEN hamartoma tumor syndrome and related neurodevelopmental genetic syndromes.

There are few well-validated measures that are appropriate for assessing the full range of neurobehavioral presentations in PTEN hamartoma tumor syndrome (PHTS) and other neurodevelopmental genetic syndromes (NDGS). As potential therapeutics are developed, having reliable, valid, free, and easily accessible measures to track a range of neurobehavioral domains will be crucial for future clinical trials. This study focused on the development and initial psychometric evaluation of a set of freely available informant-report survey scales for PHTS-the Neurobehavioral Evaluation Tool (NET). Concept elicitation, quantitative ratings, and cognitive interviewing processes were conducted with stakeholders and clinician-scientist experts, used to identify the most important neurobehavioral domains for this population, and to ensure items were appropriate for the full range of individuals with PHTS. Results of this process identified a PHTS neurobehavioral impact model with 11 domains. The final NET scales assessing these domains were administered to a sample of 384 participants (median completion time = 20.6 min), including 32 people with PHTS, 141 with other NDGS, 47 with idiopathic neurodevelopmental disorder (NDD), and 164 neurotypical controls. Initial psychometric results for the total scores of each scale indicated very good model (ω = 0.83-0.99) and internal consistency reliability (α = 0.82-0.98) as well as excellent test-retest reproducibility at 1-month follow-up (r = 0.78-0.98) and stability at 4-month follow-up (r = 0.76-0.96). Conditional reliability estimates indicated very strong measurement precision in key score ranges for assessing PHTS and other people with NDGS and/or idiopathic NDD. Comparisons across domains between PHTS and the other groups revealed specific patterns of symptoms and functioning, including lower levels of challenging behavior and more developed daily living and executive functioning skills relative to other NDGS. The NET appears to be a reliable and potentially useful tool for clinical characterization and monitoring of neurobehavioral symptoms in PHTS and may also have utility in the assessment of other NDGS and idiopathic NDD. Additional validation work, including convergent and discriminant validity analyses, are needed to replicate and extend these observations.

The Autism Symptom Dimensions Questionnaire: Development and psychometric evaluation of a new, open-source measure of autism symptomatology.

AIM: To describe the development and initial psychometric evaluation of a new, freely available measure, the Autism Symptom Dimensions Questionnaire (ASDQ). METHOD: After development and revision of an initial 33-item version, informants completed a revised 39-item version of the ASDQ on 1467 children and adolescents (aged 2-17 years), including 104 with autism spectrum disorder (ASD). RESULTS: The initial 33-item version of the ASDQ had good reliability and construct validity. However, only four specific symptom factors were identified, potentially due to an insufficient number of items. Factor analyses of the expanded instrument identified a general ASD factor and nine specific symptom factors with good measurement invariance across demographic groups. Scales showed good-to-excellent overall and conditional reliability. Exploratory analyses of predictive validity for ASD versus neurotypical and other developmental disability diagnoses indicated good accuracy for population and at-risk contexts. INTERPRETATION: The ASDQ is a free and psychometrically sound informant report instrument with good reliability of measurement across a continuous range of scores and preliminary evidence of predictive validity. The measure may be a useful alternative to existing autism symptom measures but further studies with comparison of clinical diagnoses using criterion-standard instruments are needed. WHAT THIS PAPER ADDS: The Autism Symptom Dimensions Questionnaire (ASDQ) is a new, freely available measure of autism symptoms. The ASDQ showed reliable and accurate measurement of autism symptoms. The measure had good screening efficiency for autism spectrum disorder relative to other developmental conditions.

Toward better characterization of restricted and repetitive behaviors in individuals with germline heterozygous PTEN mutations.

This study aimed to further our understanding of restricted and repetitive behaviors (RRB) among individuals with germline pathogenic mutations in PTEN by providing multimethod characterization and comparison of key RRB subdomains across individuals with PTEN mutations with autism spectrum disorder (ASD) (PTEN-ASD), with PTEN mutations without ASD (PTEN-No ASD) and with ASD and macrocephaly but without PTEN mutations (Macro-ASD). Of 86 total research participants, 38 had PTEN-ASD (Mage  = 8.93 years, SDage  = 4.75), 25 Macro-ASD (Mage  = 11.99 years; SDage  = 5.15), and 23 PTEN-No ASD (Mage  = 8.94 years; SDage  = 4.85). The Repetitive Behavior Scale-Revised (RBS-R) and the Autism Diagnostic Interview-Revised (ADI-R) were used as measures of distinct RRB domains. There were significant group differences in the RBS-R repetitive motor behaviors (RMB; F = 4.52, p = 0.014, ω2  = 0.08), insistence on sameness (IS; F = 4.11, p = 0.02, ω2  = 0.05), and circumscribed interests (CI; F = 7.80, p = 0.001, ω2  = 0.14) scales. Post hoc comparisons showed that the PTEN-No ASD group had significantly lower RMB, IS, and CI scores compared to both PTEN-ASD and Macro-ASD groups. Importantly, PTEN-No ASD group still showed elevated RRB levels. Furthermore, there was a portion of individuals in PTEN-No ASD group whose Full-Scale Intelligence Quotient (FSIQ) was >70 that did not show floor level scores in the RMB domain. After adjusting for age and FSIQ scores, group differences were no longer statistically significant. RMB, IS, and CI domains showed distinct association patterns with sex, age, and FSIQ. This investigation provides the largest and most comprehensive characterization of distinct RRB domains in individuals with PTEN mutations to date. Despite the limitations, our findings have important assessment and treatment implications.

Investigating associations between birth order and autism diagnostic phenotypes.

BACKGROUND: Birth order effects have been linked to variability in intelligence, educational attainment and sexual orientation. First- and later-born children have been linked to an increased likelihood of an Autism Spectrum Disorder (ASD) diagnosis, with a smaller body of evidence implicating decreases in cognitive functioning with increased birth order. The present study investigated the potential association between birth order and ASD diagnostic phenotypes in a large and representative population sample. METHODS: Data were obtained from an ongoing prospective diagnostic registry, collected between 1999 and 2017, including children (1-18 years of age, n = 5,404) diagnosed with ASD in the state of Western Australia. Children with ASD were ranked relative to sibling's birth to establish birth order within families at time of ASD diagnosis. Information reported to the registry by health professionals at the time of diagnostic evaluation included demographic and family characteristics, functional abilities and intellectual capacity. RESULTS: Adaptive functioning and intelligence scores decreased with increasing birth order, with later-born children more likely to have an intellectual disability. Compared to first-born children with siblings, first-born children without siblings at the time of diagnosis also exhibited decreased cognitive functioning. CONCLUSIONS: These findings demonstrate for the first time an association between increasing birth order and variability in ASD clinical phenotypes at diagnosis, with potential evidence of reproductive curtailment in children without siblings. Taken together, these findings have significant implications for advancing understanding about the potential mechanisms that contribute to heterogeneity in ASD clinical presentations as a function of birth order and family size.

Quantifying Research Domain Criteria Social Communication Subconstructs Using the Social Communication Questionnaire in Youth.

Research Domain Criteria (RDoC) has posited a set of social dimensions that could be useful in identifying sources of individual variation in social impairments across neurodevelopmental disorders. The current investigation aimed to derive estimates of the RDoC social constructs from the Social Communication Questionnaire (SCQ) and examine whether RDoC social processes, as captured by the SCQ, are best represented by a dimensional, categorical, or hybrid model. Individual SCQ items from 4 databases were combined resulting in a total of 26,407 individuals (Mage = 8.13 years, SDage = 4.19; 69.1% male). The sample consisted of 60.0% of individuals with autism spectrum disorder (ASD), 6.8% with a range of neurodevelopmental disorders and 33.2% of siblings of individuals with ASD. Comparison of a range of factor solutions through the use of exploratory structural equation modeling and confirmatory factor analysis indicated that a 3-factor structure with separate attachment and affiliation, production of nonfacial and facial communication factors provided excellent fit to the data (comparative fit index = .989, Tucker-Lewis index = .984, root mean square error of approximation = .045). and robustness across clinical groups, age, sex, and verbal status. Comparison between the best-fitting factor analysis, latent class analysis, and factor mixture analysis solutions demonstrated that the RDoC social processes domain is best represented as dimensional. Our findings show promise for capturing some of the important RDoC social constructs using the SCQ but also highlight crucial areas for the development of new, dedicated dimensional measures.

Deconstructing the repetitive behaviour phenotype in autism spectrum disorder through a large population-based analysis.

OBJECTIVE: Restricted and repetitive pattern of behaviours and interests (RRB) are a cardinal feature of autism spectrum disorder (ASD), but there remains uncertainty about how these diverse behaviours vary according to individual characteristics. This study provided the largest exploration to date of the relationship between Repetitive Motor Behaviours, Rigidity/Insistence on Sameness and Circumscribed Interests with other individual characteristics in newly diagnosed individuals with ASD. METHOD: Participants (N = 3,647; 17.7% females; Mage = 6.6 years [SD = 4.7]) were part of the Western Australian (WA) Register for ASD, an independent, prospective collection of demographic and diagnostic data of newly diagnosed cases of ASD in WA. Diagnosticians rated each of the DSM-IV-TR criteria on a 4-point Likert severity scale, and here we focused on the Repetitive Motor Behaviours, Insistence on Sameness and Circumscribed Interests symptoms. RESULTS: The associations between RRB domains, indexed by Kendall's Tau, were weak, ranging from non-significant for both Circumscribed Interests and Repetitive Motor Behaviours to significant (.20) for Insistence on Sameness and Repetitive Motor Behaviours. Older age at diagnosis was significantly associated with lower Circumscribed Interests and significantly associated with higher Insistence on Sameness and Repetitive Motor Behaviours. Male sex was significantly associated with higher Repetitive Motor Behaviours but not Insistence on Sameness or Circumscribed Interests. CONCLUSIONS: The pattern of associations identified in this study provides suggestive evidence for the distinctiveness of Repetitive Motor Behaviours, Insistence on Sameness and Circumscribed Interests, highlighting the potential utility of RRB domains for stratifying the larger ASD population into smaller, more phenotypically homogeneous subgroups that can help to facilitate efforts to understand diverse ASD aetiology and inform design of future interventions.

Parental education accounts for variability in the IQs of probands with Down syndrome: A longitudinal study.

Recent work has demonstrated that variability in probands' phenotypes, including physical features, cognitive abilities, social functioning, and other developmental domains, is influenced by parental traits. Here we examine the role of parental education as a factor contributing to the variability of intelligence quotient (IQ) of offspring with trisomy 21. Participants were 43 probands with trisomy 21, aged 4-21 years of age, and their parents. Data were collected on parental education, and a bi-parental mean education score (BMES) was calculated. Probands' cognitive abilities were assessed by the Stanford-Binet 4th edition at baseline (T1), and again 24 months later (T2). Probands were placed into one of two age groups: 4-12 years and 13-21 years. Results indicated higher parent-proband correlations in Age Group 2 (mean r = .47) relative to Age Group 1 (mean r = .33) and increasing parent-proband correlations across time, with mean correlations of Age Group 1, T1: r = .26, T2: 39; Age Group 2 T1: r = .49, T2: r = 46. Despite the expected IQ deficits observed in trisomy 21 probands, parental education may still contribute to the variability of probands' cognitive abilities. These findings are consistent with the literature noting increasing heritability of IQ with development.

Dimensional assessment of schizotypal, psychotic, and other psychiatric traits in children and their parents: development and validation of the Childhood Oxford-Liverpool Inventory of Feelings and Experiences on a representative US sample.

BACKGROUND: Healthy functioning relies on a variety of perceptual, cognitive, emotional, and behavioral abilities that are distributed throughout the normal population. Variation in these traits define the wide range of neurodevelopmental (NDD) and neuropsychiatric (NPD) disorders. Here, we introduce a new measure for assessing these traits in typically developing children and children at risk for NDD and NPD from age 2 to 18 years. METHOD: The Childhood Oxford-Liverpool Inventory of Feelings and Experiences (CO-LIFE) was created as a dimensional, parent-report measure of schizotypal and psychotic traits in the general population. Parents of 2,786 children also self-reported on an adapted version of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE-US). RESULTS: The CO-LIFE resulted in continuous distributions for the total score and for each of three factor analytically-derived subscales. Item response theory (IRT) analyses indicated strong reliability across the score range for the O-LIFE-US and the CO-LIFE. Internal consistency and test-retest reliability were high across all scales. Parent-child intraclass correlations were consistent with high heritability. The scales discriminated participants who reported a lifetime psychiatric diagnosis from those who reported no diagnosis. The O-LIFE-US and CO-LIFE scores correlated positively with the Social Responsiveness Scale 2 (SRS-2) indicating good convergent validity. CONCLUSIONS: Like the original O-LIFE, the O-LIFE-US and the CO-LIFE are valid and reliable tools that reflect the spectrum of psychiatric and schizotypal traits in the general population. Such scales are necessary for conducting family studies that aim to examine a range of psychological and behavioral traits in both children and adults and are well-suited for the Research Domain Criteria (RDoC) initiative of the NIMH.

Risk and protective factors underlying depression and suicidal ideation in Autism Spectrum Disorder.

BACKGROUND: People with Autism Spectrum Disorder (ASD) are at significantly increased risk of suicidal thoughts and behavior. Given that social difficulties in ASD often lead to social isolation, which can in turn increase the risk for depression, this study examined loneliness and social support as potential risk and protective factors associated with depression and suicidal ideation. METHOD: The sample comprised 185 people (92 females) with ASD aged 14 to 80 years who were participating in a national survey. RESULTS: Forty-nine percent of participants returned scores in the clinical range for depression and 36% reported recent suicidal ideation. Females, comprising almost 50% of the sample, returned higher depression scores than males, however no differences were identified between males and females in terms of suicidal ideation. Regression analyses revealed that loneliness, satisfaction with social support, and ASD traits predicted depression scores. Satisfaction with social support predicted suicidal ideation, however, it was no longer a significant predictor after the effects of depression were taken into account. Path analysis showed that ASD trait severity was independently related to depression, that the effect of number of social supports on depression was mediated by loneliness and satisfaction with social support, and that effects of loneliness and satisfaction with social support on suicidal ideation were mediated by depression. The pattern of relationships was nearly identical for males and females. CONCLUSIONS: This study supports a model whereby loneliness and social support operate respectively as protective and risk factors for depression and suicidal ideation in ASD.

Practitioner Review: Multilingualism and neurodevelopmental disorders - an overview of recent research and discussion of clinical implications.

BACKGROUND: Language and communication skills are essential aspects of child development, which are often disrupted in children with neurodevelopmental disorders. Cutting edge research in psycholinguistics suggests that multilingualism has potential to influence social, linguistic and cognitive development. Thus, multilingualism has implications for clinical assessment, diagnostic formulation, intervention and support offered to families. We present a systematic review and synthesis of the effects of multilingualism for children with neurodevelopmental disorders and discuss clinical implications. METHODS: We conducted systematic searches for studies on multilingualism in neurodevelopmental disorders. Keywords for neurodevelopmental disorders were based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition categories as follows; Intellectual Disabilities, Communication Disorders, Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder, Specific Learning Disorder, Motor Disorders, Other Neurodevelopmental Disorders. We included only studies based on empirical research and published in peer-reviewed journals. RESULTS: Fifty studies met inclusion criteria. Thirty-eight studies explored multilingualism in Communication Disorders, 10 in ASD and two in Intellectual Disability. No studies on multilingualism in Specific Learning Disorder or Motor Disorders were identified. Studies which found a disadvantage for multilingual children with neurodevelopmental disorders were rare, and there appears little reason to assume that multilingualism has negative effects on various aspects of functioning across a range of conditions. In fact, when considering only those studies which have compared a multilingual group with developmental disorders to a monolingual group with similar disorders, the findings consistently show no adverse effects on language development or other aspects of functioning. In the case of ASD, a positive effect on communication and social functioning has been observed. CONCLUSIONS: There is little evidence to support the widely held view that multilingual exposure is detrimental to the linguistic or social development of individuals with neurodevelopmental disorders. However, we also note that the available pool of studies is small and the number of methodologically high quality studies is relatively low. We discuss implications of multilingualism for clinical management of neurodevelopmental disorders, and discuss possible directions for future research.

A repeated cross-sectional study of daily activities of autistic adults.

It is crucial to arrive at a comprehensive understanding of the types of daily activities autistic adults typically engage in. However, previous research has almost exclusively focused on vocational or education activities. Further, it remains unclear how and whether specific daily activities participation rates change proportionally over time, vary by gender, or compare to nationally representative data. Utilizing eight annual data waves from the Netherlands Autism Register (NAR) this study aims to bridge this gap. Participants were 2449 autistic adults who indicated their participation in 18 daily activities. Results suggest that autistic adults engaged most frequently in vocational activities (e.g., paid employment, study) and participation rates were stable over time. Participation rates in non-vocational activities (e.g., hobbies, homemaking) fluctuated proportionally over time, with reports of no structured daytime activities reducing over time. Labor force participation amongst NAR participants was significantly lower than Dutch population data for the same time periods. Unemployment rates fluctuated, and were significantly higher than population data, but not for all time points. Females compared to males were overrepresented in unpaid daily activities (e.g., study, volunteer, housemaker) and work incapacitation, and underrepresented in paid employment. Employment differences in gender corresponded to national data. These findings characterize more clearly the daily activities of autistic adults, and highlights areas where support may have greater impact (e.g., females in employment).

The Neurodiversity Attitudes Questionnaire: Development and Initial Validation.

LAY ABSTRACT: Neurodiversity refers to the idea that brain differences (including disabilities) are valuable and should be accepted. Attitudes toward neurodiversity can have real-life impacts on the lives of neurodivergent people (those whose brains do not fit society's "standard"). These impacts can include effects on daily interactions, as well as how professionals such as teachers and doctors deliver services to neurodivergent people. In order to identify negative attitudes toward neurodiversity and potentially improve them, we first need to measure these attitudes. This article describes the development of the Neurodiversity Attitudes Questionnaire (NDAQ). NDAQ development included revision of questionnaire items based on feedback from experts and neurodivergent people, systematically evaluating the way participants responded to questionnaire items, and analysis of how the NDAQ items are grouped into different factors. A preliminary analysis with 351 individuals mostly living in the United States who were currently working or planning to work in a helping profession (e.g. doctors, teachers, therapists, and so on) indicates that the NDAQ measures attitudes toward neurodiversity, is well understood by participants, and fits a five-factor structure. While the NDAQ represents the first instrument designed to specifically assess attitudes toward the broad idea of neurodiversity, further work is still needed.

Employment profiles of autistic people: An 8-year longitudinal study.

LAY ABSTRACT: Autistic adults experience difficulties finding and keeping employment. However, research investigating reasons that might explain this difficulty produce mixed results. We gave a survey to 2449 autistic adults and used a statistic method to group them based on their employment status over 8 years. We identified four employment groups that best captured the experiences of autistic adults; this included a group that experienced stable unemployment, a group that experienced stable employment, a group that had high employment that reduced over time, and a group whose employment increased over the 8 years. Further analysis showed that those with fewer autistic traits, younger age, male gender, higher education, later diagnosis age and no co-occurring conditions were more likely to have stable employment. People whose employment changed over time were more likely to have a higher level of education than the stable unemployment group, and those in the increasing employment group were younger age and had no co-occurring conditions. These findings help us better understand that not all autistic adults' experiences of employment are the same, which helps focus where employment programmes and support may be most needed, for example, people who identify as women or have a co-occurring condition.

Predictors of Change in Wellbeing and Mental Health of Parents of Autistic Pre-Schoolers.

Parenting is a rewarding experience but is not without its challenges. Parents of Autistic children face additional challenges, and as a result can experience lower levels of wellbeing and more mental health problems (i.e., depression, anxiety, stress). Previous studies have identified concurrent correlates of wellbeing and mental health. However, few have investigated predictors of subsequent wellbeing and mental health, or of change over time, among parents of pre-school aged autistic children. We examined child-, parent-, and family/sociodemographic factors associated with change in parents' mental health and wellbeing across three timepoints (spanning approximately one year) among 53 parents of Autistic pre-schoolers (M = 35.48, SD = 6.36 months. At each timepoint, parents reported lower wellbeing and greater mental health difficulties compared to normative data. There was no significant group-level change over time in parent outcomes. However, individual variability in short-term (~ 5 months) wellbeing and mental health change was predicted by a combination of child- and parent-related factors, while variability in medium-term (~ 10 months) change was predicted by parent factors alone. Parents' description of their child and their relationship predicted change in both wellbeing and mental health. Furthermore, participating in a parent-mediated intervention (available to a subgroup) was a significant predictor of change in wellbeing. Our findings highlight potentially modifiable factors (e.g., learning healthier coping strategies) that may positively impact both short- and medium-term change in parental outcomes.

Characterizing associations between emotion dysregulation, anxiety, and repetitive behaviors in autistic youth with intellectual disability.

There is a paucity of research that explores associations between emotion dysregulation and the expression and severity of core and co-occurring characteristics of autism spectrum disorder (ASD), especially in autistic youth with co-occurring intellectual disability (ID). This study explored the interplay between developmental characteristics and emotion dysregulation, anxiety, and specific subtypes of RRBs that are elevated in autistic youth with co-occurring ID. Generalized additive models demonstrated that age, sex, language level, dysregulation, and anxiety showed unique patterns of association with subtypes of RRBs in a sample of 150 autistic youth with co-occurring ID who are non-speaking or minimally verbal. More specifically, higher anxiety levels were significantly associated with elevations in repetitive sensory motor behaviors (RSMB), self-injurious behaviors (SIB), insistence on sameness (IS), and unusual interests (UI). While emotion dysregulation was a significant predictor of UI, it demonstrated positive, albeit not significant, associations with the intensity of SIB and RSMB. Language level was a significant predictor of RSMB, such that the intensity of RSMB was higher for individuals who were non-speaking relative to those who spoke in single words. These findings provide preliminary insights into patterns of associations between emotion dysregulation, anxiety, and specific subdomains of RRBs in autistic youth with ID.

Are restricted and repetitive behaviours in two- and six-year-olds associated with emotional and behavioural difficulties?

Background: Restricted and repetitive patterns of behaviour (RRBs) serve an adaptive role in development. Elevated levels of RRBs beyond the early years, however, are associated with poorer outcome in language, cognition, and wellbeing, and are seen across a range of neurodevelopmental conditions. This study aimed to characterize the association of distinct RRB subtypes at two and six years of age, with internalising and externalising difficulties in a community sample of children. Methods: 485 parents reported on their child's insistence on sameness (IS) and repetitive sensory and motor (RSM) RRBs at two and six years of age using the Repetitive Behaviour Questionnaire (RBQ-2). Emotional and behavioural difficulties were measured using the Strengths and Difficulties Questionnaire (SDQ) at age six. Results: Consistent with previous research, RRBs later in development better predicted emotional and behavioural difficulties at age six than RRBs earlier in development. Moreover, IS RRBs were selectively associated with internalising behaviours and RSM RRBs with externalising behaviours. Importantly, these selective associations depended on when RRBs were measured. Only IS RRBs at age six were significantly associated with internalising behaviour. By contrast, while more RSM RRBs at age six were associated with higher rates of externalising behaviours, higher rates of RSM RRBs at age two were associated with fewer externalising behaviours, adding further support to the previously reported adaptive role of RRBs in early behaviour regulation. Conclusion: Although there is a need for further research to provide a detailed profile of the adaptive periods for IS and RSM RRBs, the present findings support the potential utility of elevated RRBs as a signal for emotional and behavioural difficulties at age six.

Assessing pragmatic language difficulties using the Revised Children's Communication Checklist-2. Exploratory structural equation modeling and associations with restricted and repetitive behaviors.

In this paper, we investigated the psychometric properties of the Child Communication Checklist-Revised (CCC-R) for the first time with an English-speaking sample. We used a confirmatory application of exploratory structural equation modeling (ESEM) to re-evaluate the CCC-R's psychometric properties. We found strong support for its use as an assessment for pragmatic and structural language. Our second main aim was to explore associations between pragmatic and structural language and restricted and repetitive behaviors (RRBs), two hallmark characteristics of autism. We used the CCC-R and Repetitive Behavior Questionnaire (RBQ-2) to investigate these associations in a diverse non-clinical sample of children, taking a transdiagnostic approach. We intentionally excluded autism and other neurodevelopmental diagnoses to test, (1) the CCC-R in a broad sample and (2) the association between pragmatic language and RRB in children not already selected for that association. The sample comprised two groups of children, one was community sampled (n = 123) and the other (n = 143) included children with non-specific behavioral, emotional and/or cognitive difficulties referred to an assessment unit by schools. We found clear associations between pragmatic language difficulties and RRBs in both groups. Regression analysis showed that pragmatic language was the only significant contributor to RRBs even after Grammatical-Semantic score, age, sex, and socioeconomic status were controlled. The pattern was the same for both recruitment groups. However, the effects were stronger for the school-referred group which also had more pragmatic difficulties, grammatical-semantic difficulties and RRBs. A robust link between pragmatic language and RRBs, established in autism, has continuity across the broader non-clinical population.