The Relationship Between Intellectual Profiles, ASD Symptoms, and Age in a North American Sample of Youth with Autism Spectrum Disorder

Autism spectrum disorder (ASD) is an increasingly common neurodevelopmental disorder, estimated to occur in 1 of 68 individuals (Centers for Disease Control and Prevention [CDC], 2014). Evaluation of intellectual functioning is one component of a comprehensive evaluation for individuals with ASD and, specifically, is necessary for differential diagnosis, prognosis and selection of appropriate interventions (Filipek et al., 2000; Johnson & Myer, 2007; Klin, Saulnier, Tsatsanis, & Volkmar, 2005; Kuschner, Bennetto, & Yost, 2007; Volkmar et al., 2014). Profiles of scores on measures of intellectual functioning have the potential to aid in further understanding etiology of ASD. Research investigating the relationship between ASD symptoms and scores on measures of intellectual functioning suggests that scores on the factors comprising global measures of intellectual functioning may be related to ASD symptoms (Black, Wallace, Sokoloff, & Kenworthy, 2009; Joseph, Tager-Flusberg, & Lord, 2002). However, to date, such research has been limited by methodological problems such as the use of samples identified using unreliable subtypes of ASD (i.e., subtypes identified in the Diagnostic and Statistical Manual, 4th Edition - Text Revision (DSM-IV TR; APA, 2000) and an overreliance on variable-centered methodological strategies. This study was designed to further elucidate the relationship between scores on measures of intellectual functioning (i.e., profiles of intellectual functioning), ASD symptoms, and age. The methodology of the study was primarily designed to address previous weaknesses by applying person-centered statistical methods (i.e., latent profile analysis [LPA]) to investigate profiles of intellectual functioning in youth with ASD using a recommended measure of intellectual functioning, the Differential Ability Scales – Second Edition (Elliott, 2007a). A secondary purpose of the current study was to investigate whether age predicts profiles of intellectual functioning and to investigate whether profiles of intellectual functioning predict patterns of core ASD symptoms (i.e., social-communication and restricted/repetitive interests or behaviors). The sample (n=2121) was extracted from a sample of 2644 youth, between the ages of 4 and 18, who have relevant data points in the Simons Simplex Collection (SSC). The SSC is a multi-site, genetic research project in North America that includes families with only one child with an ASD and no other first- through third-degree relatives with ASD or suspected ASD (i.e., simplex families; Fischbach & Lord, 2010). The individuals included in the project are well characterized and the data points included for each individuals have been scrutinized at multiple levels. In order to be included in the SSC, youth necessarily met criteria for an ASD (per DSM-IV-TR criteria) based on scores from standardized diagnostic instruments and clinical opinion. LPA models suggested that a five-class solution was the best model fit for all samples (i.e., the whole sample, the early-years sample, and the school-age sample). Multinomial logistic regression models with age and measures of core ASD symptoms as predictors were significant for all samples; but, the predictive value of those measures were variable when considering the individual classes within the five-class models. The current study adds to the existing literature base by using person-centered statistical methods to clarify the relationship between profiles of scores on measures of intellectual functioning, ASD symptoms, and age. Clinical implications, limitations, and future directions are discussed.Psychological, Health, and Learning Sciences, Department o

Bias in measurement of autism symptoms by spoken language level and non-verbal mental age in minimally verbal children with neurodevelopmental disorders

Increasing numbers of children with known genetic conditions and/or intellectual disability are referred for evaluation of autism spectrum disorder (ASD), highlighting the need to refine autism symptom measures to facilitate differential diagnoses in children with cognitive and language impairments. Previous studies have reported decreased specificity of ASD screening and diagnostic measures in children with intellectual disability. However, little is known about how cognitive and language abilities impact the measurement of specific ASD symptoms in this group. We aggregated a large sample of young children (N = 1196; aged 31-119 months) to examine measurement invariance of ASD symptoms among minimally verbal children within the context of the Autism Diagnostic Observation Schedule (ADOS) Module 1. Using confirmatory factor analysis (CFA) and moderated non-linear factor analysis (MNLFA), we examined how discrete behaviors were differentially associated with the latent symptom domains of social communication impairments (SCI) and restricted and repetitive behaviors (RRB) across spoken language levels and non-verbal mental age groupings. While the two-factor structure of SCI and RRB held consistently across language and cognitive levels, only partial invariance was observed for both ASD symptom domains of SCI and RRB. Specifically, four out of the 15 SCI items and one out of the three RRB items examined showed differential item functioning between children with "Few to No Words" and those with "Some Words"; and one SCI item and one RRB item showed differential item functioning across non-verbal mental age groups. Moreover, even after adjusting for the differential item functioning to reduce measurement bias across groups, there were still differences in ASD symptom domain scores across spoken language levels. These findings further underscore the influence of spoken language level on measurement of ASD symptoms and the importance of measuring ASD symptoms within refined spoken language levels, even among those with minimal verbal abilities

CRISIS AFAR: an international collaborative study of the impact of the COVID-19 pandemic on mental health and service access in youth with autism and neurodevelopmental conditions

BackgroundHeterogeneous mental health outcomes during the COVID-19 pandemic are documented in the general population. Such heterogeneity has not been systematically assessed in youth with autism spectrum disorder (ASD) and related neurodevelopmental disorders (NDD). To identify distinct patterns of the pandemic impact and their predictors in ASD/NDD youth, we focused on pandemic-related changes in symptoms and access to services.MethodsUsing a naturalistic observational design, we assessed parent responses on the Coronavirus Health and Impact Survey Initiative (CRISIS) Adapted For Autism and Related neurodevelopmental conditions (AFAR). Cross-sectional AFAR data were aggregated across 14 European and North American sites yielding a clinically well-characterized sample of N = 1275 individuals with ASD/NDD (age = 11.0 ± 3.6 years; n females = 277). To identify subgroups with differential outcomes, we applied hierarchical clustering across eleven variables measuring changes in symptoms and access to services. Then, random forest classification assessed the importance of socio-demographics, pre-pandemic service rates, clinical severity of ASD-associated symptoms, and COVID-19 pandemic experiences/environments in predicting the outcome subgroups.ResultsClustering revealed four subgroups. One subgroup-broad symptom worsening only (20%)-included youth with worsening across a range of symptoms but with service disruptions similar to the average of the aggregate sample. The other three subgroups were, relatively, clinically stable but differed in service access: primarily modified services (23%), primarily lost services (6%), and average services/symptom changes (53%). Distinct combinations of a set of pre-pandemic services, pandemic environment (e.g., COVID-19 new cases, restrictions), experiences (e.g., COVID-19 Worries), and age predicted each outcome subgroup.LimitationsNotable limitations of the study are its cross-sectional nature and focus on the first six months of the pandemic.ConclusionsConcomitantly assessing variation in changes of symptoms and service access during the first phase of the pandemic revealed differential outcome profiles in ASD/NDD youth. Subgroups were characterized by distinct prediction patterns across a set of pre- and pandemic-related experiences/contexts. Results may inform recovery efforts and preparedness in future crises; they also underscore the critical value of international data-sharing and collaborations to address the needs of those most vulnerable in times of crisis