Developmental outcomes in adolescence of children with autism spectrum disorder without intellectual disability: A systematic review of prospective studies

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.

Subgroups of Children with Autism Spectrum Disorder without Intellectual Disability: A Longitudinal Examination of Executive and Socio-Adaptive Behaviors in Adolescence

Within the autistic spectrum, there is remarkable variability in the etiology, presentation, and treatment response. This prospective study was designed to identify, through cluster analysis, subgroups of individuals with ASD without intellectual disability (ID) based on the severity of the core symptoms in childhood. The secondary aim was to explore whether these subgroups and a group with typical development (TD) differ in cognitive, adaptive, and social aspects measured in adolescence. The sample at baseline was comprised of 52 children with ASD without ID and 37 children with TD, aged 7-11. Among the ASD group, three clusters were identified. Cluster 1 (40%), 'high severity', presented high symptom severity on the DSM-5 criteria and the Social Communication Questionnaire. Cluster 2 (34%) showed 'moderate severity' on most of the scores. Cluster 3 (25%) corresponded to 'low severity', showing moderate social impairment and low restrictive, repetitive patterns of behavior, interests and activities. At 5-year follow-up, 45 adolescents with ASD without ID and 27 adolescents with TD were assessed. All clusters had significantly more difficulties in EF, ToM, socialization and adaptive behavior compared to TD. Social and adaptive trajectories between the ASD subgroups were relatively different; Cluster 3 showed poorer socialization and daily living skills than the other two subgroups. These findings highlight the importance of fully assessing social, cognitive, and adaptive profiles to develop care plans tailored to specific needs.

Declining Trajectories of Co-occurring Psychopathology Symptoms in Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder: A 10-Year Longitudinal Study

Objective: Our objective was to examine developmental trajectories of co-occurring psychopathology symptoms from childhood to young adulthood in individuals with Attention-Deficit/Hyperactivity Disorder (ADHD), individuals with Autism Spectrum Disorder (ASD), and typically developing (TD) individuals. Method: We assessed co-occurring psychopathology symptoms in 61 individuals with ADHD, 26 with ASD, and 40 TD individuals at baseline (T1; M_age = 11.72, 64% boys), 2-year follow up (T2; M_age = 13.77), and 10-year follow up (T3; M_age = 21.35). We analyzed trajectories of internalizing behaviors, externalizing behaviors, and total problems with linear mixed models. Results: From T1 to T3, the ADHD group displayed a small decline in internalizing behaviors (d = -0.49) and large declines in externalizing behaviors (d = -0.78) and total problems (d = -0.71). The ASD group displayed large declines in internalizing behaviors (d = -0.79), externalizing behaviors (d = -0.80), and total problems (d = -0.89). From T1 to T2, the decline in externalizing behaviors and total problems were significantly smaller in the ADHD group compared with the ASD group. The ADHD and the ASD group displayed more co-occurring symptoms compared with the TD group at T3. Conclusion: Individuals with ADHD and ASD, respectively, displayed declines in co-occurring symptoms from childhood to young adulthood. Individuals with ASD displayed an earlier decline compared with individuals with ADHD. Compared with TD individuals, individuals with ADHD and ASD, respectively, continued to display elevated levels of co-occurring symptoms in young adulthood.