Autism Spectrum Disorder and IQ - A Complex Interplay

Do Wechsler intelligence scales predict academic achievement in children with ADHD or autism? A systematic review and meta-analysis

Intelligence tests predict academic achievement in typically developed children, however if this is the case also in children with attention-deficit/hyperactivity disorder (ADHD) and/or autism spectrum disorder (ASD) is not clear. This systematic review and meta-analysis examined if Wechsler intelligence scales predict academic achievement and/or grades in children, ages 6-16 years, with ADHD and/or ASD. We searched the databases PubMed, PsycINFO and Education Research Complete for studies published between 2000 and 2023. We used the Newcastle-Ottawa Scale to assess risk of bias. Narrative synthesis and meta-analysis were performed. Twelve studies (ADHD n = 1,834, ASD n = 176) were included in the review, and six samples (ADHD n = 1,112) of those were included in the meta-analyses. The results of the meta-analyses showed moderate overall weighted correlations between IQ and word reading, written language, and mathematics respectively. Similarly, the overall weighted correlations between processing speed and the aforementioned domains of academic achievement were moderate. Meta-analysis with additional Wechsler scales composite scores could not be conducted. In the narrative synthesis, Full Scale IQ was associated with academic achievement in both ADHD and ASD, and grades in ADHD. The limited number of ASD participants and the heterogeneity of the samples need to be considered when interpreting results. Generally, the results indicate that Wechsler scales are valuable in predicting academic achievement in children with ADHD or ASD. Motivation and other factors related with academic achievement need to be further explored in these groups.

Clinical gait analysis in older children with autism spectrum disorder

Individuals with autism spectrum disorder (ASD) often exhibit motor deficits that increase their risk of falls. There is a lack of understanding regarding gait biomechanics demonstrated by older children with ASD. The purpose of the study was to determine differences in gait patterns between older children with ASD and typically developing children. Eleven children with ASD and 11 age- and gender-matched typically developing children were recruited for the study. Participants walked on a force-instrumented treadmill at a constant speed (1.1 ​m/s ​- ​1.2 ​m/s) for five minutes (min). Participants performed maximal voluntary contractions to assess their knee muscular strength. Differences between individuals with ASD and matched control participants were examined through paired t-tests with a significance level of p ​≤ ​0.05. Individuals with ASD demonstrated a smaller knee extensor torque compared to controls (p ​= ​0.002). Participants with ASD exhibited a shorter stride length (p ​= ​0.04), a greater cadence (p ​= ​0.03), and a higher variation in stride width (p ​= ​0.04) compared to control participants. The individuals with ASD experienced a greater braking ground reaction force (p ​= ​0.03) during loading response. The results indicate older children with ASD develop a unique gait pattern signified by a reduced stride length, increased cadence, and an increase of variation in stride width. This unique gait pattern may represent a movement strategy used by the individuals with ASD to compensate for the weakness associated with their knee extensor muscles. Individuals with ASD who demonstrate these unique gait deviations may face reduced postural stability and an increased risk of fall-related injuries.

Using adaptive behavior scores to convey level of functioning in children with autism spectrum disorder: Evidence from the Study to Explore Early Development

LAY ABSTRACT

Autistic people are often described as "low-" or "high-functioning" based on their scores on cognitive tests. These terms are common in publications and in everyday communication. However, recent research and feedback from the autistic community suggests that relying on cognitive ability alone to describe functioning may miss meaningful differences in the abilities of autistic children and adults and in the kinds of support they may need. Additional methods are needed to describe "functioning" in autistic children. We examined whether scores from a test measuring adaptive behaviors would provide information on the functional abilities of children with autism that is different from cognitive ability and autism symptom severity. Adaptive behaviors include age-appropriate skills that allow people to function in their everyday lives and social interactions. We found that a large amount of the variation in adaptive behavior scores was not explained by cognitive development, autism symptom severity, and behavioral and emotional problems. In addition, there was a wide range of adaptive ability levels in children with autism in our study, including in those with low, average, or high cognitive scores. Our results suggest that adaptive behavior scores could provide useful information about the strengths and support needs of autistic children above and beyond measures of cognitive ability and autism symptom severity. Adaptive behavior scores provide important information on the needs of autistic people.

Cognitive functioning in adults with autism spectrum disorder

INTRODUCTION

Neuropsychological deficits in areas of Executive Functioning (EF), theory of mind, and central coherence have been well-documented among children and adolescents with autism spectrum disorder (ASD); however, there remains a significant gap in knowledge with regards to neuropsychological profile in adults with ASD. This study aims to investigate the intellectual functioning and neuropsychological profiles of a clinical population of adults with ASD.

METHODS

This cross-sectional study included 40 available autistic individuals referred to an adult developmental disorders clinic at a hospital between 2021 and 2022. All participants were assessed using the Stanford-Binet Intelligence Scale (SBIS), Autism Spectrum Quotient (AQ), Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R), and Social Responsiveness Scale (SRS).

RESULTS

Individuals with ASD exhibited lower IQ scores across all domains of the Stanford-Binet Intelligence Scale, compared to the general population, although the mean IQ scores remained within the normal range. Significant differences were observed in Full Scale IQ, Verbal IQ, Non-Verbal IQ, Fluid Reasoning, Knowledge, Quantitative Reasoning, Visual-Spatial Processing, and Working Memory compared to the general population. Additionally, autistic individuals' performance on verbal knowledge was higher compared to non-verbal knowledge. No significant correlations were found between the total and subscale scores of verbal and nonverbal IQ and AQ, RAADS-R, and SRS scores.

CONCLUSION

Considering the significant impacts of cognitive and executive function on the social and occupational aspects of autistic adults, further investigations in this area are warranted.

Category learning in autistic individuals: A meta-analysis

Learning new categories is a fundamental human skill. In the present article, we report the first comprehensive meta-analysis of category learning in autism. Including studies comparing groups of autistic and nonautistic individuals, we investigated whether autistic individuals differ in category learning from nonautistic individuals. In addition, we examined moderator variables accounting for variability between studies. A multilevel meta-analysis of k = 50 studies examining n = 1,220 autistic and n = 1,445 nonautistic individuals based on 112 effect sizes in terms of the standardized mean difference revealed lower-level category learning skills for autistic compared with nonautistic individuals, g = -0.55, 95% CI = [-0.73, -0.38], p < .0001. According to moderator analyses, the significant amount of heterogeneity, Q(111) = 617.88, p < .0001, was explained by only one of the moderator variables under investigation-namely, study language. For the remaining variables-namely, age, year of publication, risk of bias, type of control group, IQ of autistic group, percentage of male autistic participants, type of category, type of task, and type of dependent measure-there were no significant effects. Although hat values and Cook's distance statistics confirmed the robustness of findings, results of Egger's test and a funnel plot suggested the presence of publication bias reflecting an overrepresentation of disadvantageous findings for autistic groups. Objectives for future work include identifying additional moderator variables, examining downstream effects of suboptimal category learning skills, and developing interventions.

Classifying autism in a clinical population based on motion synchrony: a proof-of-concept study using real-life diagnostic interviews

Predictive modeling strategies are increasingly studied as a means to overcome clinical bottlenecks in the diagnostic classification of autism spectrum disorder. However, while some findings are promising in the light of diagnostic marker research, many of these approaches lack the scalability for adequate and effective translation to everyday clinical practice. In this study, our aim was to explore the use of objective computer vision video analysis of real-world autism diagnostic interviews in a clinical sample of children and young individuals in the transition to adulthood to predict diagnosis. Specifically, we trained a support vector machine learning model on interpersonal synchrony data recorded in Autism Diagnostic Observation Schedule (ADOS-2) interviews of patient-clinician dyads. Our model was able to classify dyads involving an autistic patient (n = 56) with a balanced accuracy of 63.4% against dyads including a patient with other psychiatric diagnoses (n = 38). Further analyses revealed no significant associations between our classification metrics with clinical ratings. We argue that, given the above-chance performance of our classifier in a highly heterogeneous sample both in age and diagnosis, with few adjustments this highly scalable approach presents a viable route for future diagnostic marker research in autism.

Volume-based and Surface-Based Methods in Autism Compared with Healthy Controls Are Free surfer and CAT12 in Agreement?

Objectives

Autism Spectrum Disorder (ASD) encompasses a range of neurodevelopmental disorders, and early detection is crucial. This study aims to identify the Regions of Interest (ROIs) with significant differences between healthy controls and individuals with autism, as well as evaluate the agreement between FreeSurfer 6 (FS6) and Computational Anatomy Toolbox (CAT12) methods.

Materials & Methods

Surface-based and volume-based features were extracted from FS software and CAT12 toolbox for Statistical Parametric Mapping (SPM) software to estimate ROI-wise biomarkers. These biomarkers were compared between 18 males Typically Developing Controls (TDCs) and 40 male subjects with ASD to assess group differences for each method. Finally, agreement and regression analyses were performed between the two methods for TDCs and ASD groups.

Results

Both methods revealed ROIs with significant differences for each parameter. The Analysis of Covariance (ANCOVA) showed that both TDCs and ASD groups indicated a significant relationship between the two methods (p<0.001). The R2 values for TDCs and ASD groups were 0.692 and 0.680, respectively, demonstrating a moderate correlation between CAT12 and FS6. Bland-Altman graphs showed a moderate level of agreement between the two methods.

Conclusion

The moderate correlation and agreement between CAT12 and FS6 suggest that while some consistency is observed in the results, CAT12 is not a superior substitute for FS6 software. Further research is needed to identify a potential replacement for this method.

Females evaluated for autism: characteristics and co-occurring and differential DSM-5 diagnoses

Objective: While sex differences in autism spectrum disorder (ASD) have been identified in areas such as neurocognitive functioning, behavior patterns, and diagnostic criteria, less work has focused on differences within females referred for ASD evaluation, including those who did not go on to receive a diagnosis. This study examined psychological and behavioral characteristics and co-occurring and differential DSM-5 diagnoses between pediatric female participants who received an ASD diagnosis (ASD+) and those who did not (ASD-). Method: Data on cognitive functioning, adaptive functioning, internalizing symptoms, externalizing symptoms, and ADOS-2 scores were analyzed among 137 3- to 20-year-old patients. The sample was divided into two age groups (ages 3-8 and ages 9-20) for analyses of between-group differences (ASD+ vs. ASD-) and predictors of group membership. Results: Females in the ASD+ group were significantly younger, had lower cognitive scores, lower internalizing and externalizing symptoms, and had higher Autism Diagnostic Observation Schedule-2 (ADOS-2) scores than those in the ASD- group. ADOS-2 scores were also the only significant predictor of ASD group membership across age groups. The ASD+ group had a higher percentage of intellectual disability while the ASD- group had higher percentages of anxiety disorder, attention-deficit/hyperactivity disorder, and disruptive behavior disorders. Conclusions: Psychological and behavioral presentations among females referred for ASD evaluation varied with age and ASD diagnostic groups. These results highlight potential female differences in ASD referrals and identification of ASD and the need to improve care for females in consideration of demographic factors.

Characterizing Subcortical Structural Heterogeneity in Autism

Autism presents with significant phenotypic and neuroanatomical heterogeneity, and neuroimaging studies of the thalamus, globus pallidus and striatum in autism have produced inconsistent and contradictory results. These structures are critical mediators of functions known to be atypical in autism, including sensory gating and motor function. We examined both volumetric and fine-grained localized shape differences in autism using a large (n=3145, 1045-1318 after strict quality control), cross-sectional dataset of T1-weighted structural MRI scans from 32 sites, including both males and females (assigned-at-birth). We investigated three potentially important sources of neuroanatomical heterogeneity: sex, age, and intelligence quotient (IQ), using a meta-analytic technique after strict quality control to minimize non-biological sources of variation. We observed no volumetric differences in the thalamus, globus pallidus, or striatum in autism. Rather, we identified a variety of localized shape differences in all three structures. Including age, but not sex or IQ, in the statistical model improved the fit for both the pallidum and striatum, but not for the thalamus. Age-centered shape analysis indicated a variety of age-dependent regional differences. Overall, our findings help confirm that the neurodevelopment of the striatum, globus pallidus and thalamus are atypical in autism, in a subtle location-dependent manner that is not reflected in overall structure volumes, and that is highly non-uniform across the lifespan.

Association Between Intellectual Functioning and Autistic Traits in the General Population of Children

Autistic traits are continuously distributed in the general population. The associations between autistic traits and intellectual functioning and/or behavioural difficulties, and the impact of intellectual functioning on behavioural difficulties are unclear. The study aims to describe the distribution of autistic traits in a population-based cross-sectional sample of children. Further aims are to examine the association between intellectual functioning and autistic traits, and between autistic traits and behavioural difficulties. Wechsler scales and ratings of autistic traits and behavioural problems in 874 children aged 7-9 years in the Swedish Environmental Longitudinal Mother and Child, Asthma and Allergy (SELMA) study were assessed. We found a continuous distribution of autistic traits. Intellectual functioning was negatively associated with autistic traits but not with behavioural difficulties. Behavioural difficulties were associated with autistic traits.

The Healthcare Experience of Autistic Patients in Orthopaedic Surgery and Closely Related Fields: A Scoping Review

Orthopaedic and related care has the potential to present unique obstacles for patients with a range of autism manifestations. In this review, we aim to describe and analyze the literature on autistic patients' experience within orthopaedics and closely related fields. This literature search utilized the PubMed, Embase, and Cumulative Index to Nursing and Allied Health Literature databases. Three major concepts were built into the search terms: (1) patients on the autism spectrum; (2) patient experience; and (3) movement sciences, including orthopaedics, physical medicine and rehabilitation (PM&R), occupational therapy (OT), and physical therapy (PT). Our search yielded 35 topical publications, with the major topic areas addressed as follows: (1) clinical and perioperative management, (2) therapy interventions, (3) participation in exercise and social play, (4) sensory management and accommodations, (5) caregiver/parent training and involvement in care, (6) healthcare needs and barriers to care, and (7) utilization of technology. In the current literature, there are no studies that attempt to directly assess autistic patient experience with care practices and clinical environments in orthopaedics. Rigorous, direct examination of the experience of autistic patients within clinical orthopaedic settings is urgently needed to address this gap.