The functional impact of cognition in adults with autism spectrum disorders

Cognitive functioning in adult psychiatric patients with and without attention-deficit/hyperactivity disorder

INTRODUCTION

Studies of cognitive functioning in patients with attention-deficit/hyperactivity disorder (ADHD) have often used healthy comparison groups. The present study examines cognitive profiles, including general intellectual and executive functions, in a young adult psychiatric outpatient clientele with ADHD and evaluates whether their cognitive profiles can help differentiate them from patients with non-ADHD-associated psychiatric disorders.

METHODS

The study group comprised 141 young adult psychiatric patients (age range 18-25 years) of whom 78 had ADHD. Comprehensive neuropsychological assessment included the Wechsler Adult Intelligence Scale, 4th version and subtests from Delis-Kaplan Executive Function System. Clinical psychiatric assessments and diagnostic evaluation were performed.

RESULTS

The ADHD group (including all subtypes) had significantly lower verbal comprehension and full-scale intelligence quotient than the non-ADHD group. Tests measuring working memory or executive function did not separate those with and without ADHD.

CONCLUSION

The results of our study suggest that, except for the need to establish overall cognitive performance level, the clinical implication of testing is small if the purpose is to "rule out" an ADHD diagnosis.

Cognitive Profile in Autism and ADHD: A Meta-Analysis of Performance on the WAIS-IV and WISC-V

OBJECTIVE

Previous research has suggested that neurodevelopmental conditions may be associated with distinctive cognitive profiles on the Wechsler intelligence tests (of which the most recent editions are the WAIS-IV and WISC-V). However, the extent to which a cognitive profile can be reliably identified for individuals meeting criteria for autism or ADHD remains unclear. The present review investigated this issue.

METHOD

A search was conducted in PsycInfo, Embase, and Medline in October 2022 for papers reporting the performance of children or adults diagnosed with autism or ADHD on the WAIS-IV or the WISC-V. Test scores were aggregated using meta-analysis.

RESULTS

Scores were analyzed from over 1,800 neurodivergent people reported across 18 data sources. Autistic children and adults performed in the typical range for verbal and nonverbal reasoning, but scored ~1 SD below the mean for processing speed and had slightly reduced scores on working memory. This provides evidence for a "spiky" cognitive profile in autism. Performance of children and adults with ADHD was mostly at age-expected levels, with slightly reduced scores for working memory.

CONCLUSION

Although the pattern of performance on the Wechsler tests is not sufficiently sensitive or specific to use for diagnostic purposes, autism appears to be associated with a cognitive profile of relative strengths in verbal and nonverbal reasoning and a weakness in processing speed. Attention deficit hyperactivity disorder appears less associated with a particular cognitive profile. Autistic individuals may especially benefit from a cognitive assessment to identify and support with their strengths and difficulties.

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.

Feasibility, Acceptability and Preliminary Efficacy of Dialectical Behavior Therapy for Autistic Adults without Intellectual Disability: A Mixed Methods Study

Self-harm and suicidal behaviors are prevalent among autistic adults without intellectual disability (ID). Emotion dysregulation (ED), the difficulty in modulating emotions, has been identified as an important risk factor. Dialectical behavior therapy (DBT) has been proved effective to treat ED in disorders other than autism spectrum disorder. Our study aimed at assessing the feasibility, acceptability and preliminary efficacy of DBT in seven autistic adults without ID exhibiting self-harm and/or suicidal behaviors linked to severe ED. Our results suggest that DBT is feasible and highly acceptable to autistic adults without ID. Additionally, mean scores on the Difficulties in Emotion Regulation Scale decreased significantly post-treatment and at 4-month follow-up, suggesting that DBT might be efficacious in reducing ED in this population.

Differences in daily life executive functioning between people with autism and people with schizophrenia

This is a comparative analysis of everyday executive functioning between individuals with Autism Spectrum Disorder (ASD), Schizophrenia Spectrum Disorders (SSD) and controls using Dysexecutive Questionnaire-Spanish (DEX-Sp), to identify patterns of difficulties. Also we assessed the relationship between EF and adaptive behavior as measured by the Vineland Adaptive Behavioral Scale-II. Common areas of everyday executive functions were established as problematic in individuals with ASD and SSD related to Disinhibition and Apathy, while Disorganization and Impulsivity was gravely affected in ASD group only. The degree of Dysexecutive Syndrome was predictive of adaptive behavior in ASD group only. These suggest that DEX-Sp could be a useful tool in differentiating areas of strength and weaknesses in clinical groups such as ASD and SDD.

Predictive waves in the autism-schizophrenia continuum: A novel biobehavioral model

The brain is a predictive machine. Converging data suggests a diametric predictive strategy from autism spectrum disorders (ASD) to schizophrenic spectrum disorders (SSD). Whereas perceptual inference in ASD is rigidly shaped by incoming sensory information, the SSD population is prone to overestimate the precision of their priors' models. Growing evidence considers brain oscillations pivotal biomarkers to understand how top-down predictions integrate bottom-up input. Starting from the conceptualization of ASD and SSD as oscillopathies, we introduce an integrated perspective that ascribes the maladjustments of the predictive mechanism to dysregulation of neural synchronization. According to this proposal, disturbances in the oscillatory profile do not allow the appropriate trade-off between descending predictive signal, overweighted in SSD, and ascending prediction errors, overweighted in ASD. These opposing imbalances both result in an ill-adapted reaction to external challenges. This approach offers a neuro-computational model capable of linking predictive coding theories with electrophysiological findings, aiming to increase knowledge on the neuronal foundations of the two spectra features and stimulate hypothesis-driven rehabilitation/research perspectives.

Symptomatic, Genetic, and Mechanistic Overlaps between Autism and Alzheimer's Disease

Autism spectrum disorder (ASD) and Alzheimer's disease (AD) are neurodevelopmental and neurodegenerative disorders affecting two opposite ends of life span, i.e., childhood and old age. Both disorders pose a cumulative threat to human health, with the rate of incidences increasing considerably worldwide. In the context of recent developments, we aimed to review correlated symptoms and genetics, and overlapping aspects in the mechanisms of the pathogenesis of ASD and AD. Dementia, insomnia, and weak neuromuscular interaction, as well as communicative and cognitive impairments, are shared symptoms. A number of genes and proteins linked with both disorders have been tabulated, including MECP2, ADNP, SCN2A, NLGN, SHANK, PTEN, RELN, and FMR1. Theories about the role of neuron development, processing, connectivity, and levels of neurotransmitters in both disorders have been discussed. Based on the recent literature, the roles of FMRP (Fragile X mental retardation protein), hnRNPC (heterogeneous ribonucleoprotein-C), IRP (Iron regulatory proteins), miRNAs (MicroRNAs), and α-, β0, and γ-secretases in the posttranscriptional regulation of cellular synthesis and processing of APP (amyloid-β precursor protein) have been elaborated to describe the parallel and overlapping routes and mechanisms of ASD and AD pathogenesis. However, the interactive role of genetic and environmental factors, oxidative and metal ion stress, mutations in the associated genes, and alterations in the related cellular pathways in the development of ASD and AD needs further investigation.

Frontoparietal Network Connectivity During an N-Back Task in Adults With Autism Spectrum Disorder

BACKGROUND

Short-term and working memory (STM and WM) deficits have been demonstrated in individuals with autism spectrum disorder (ASD) and may emerge through atypical functional activity and connectivity of the frontoparietal network, which exerts top-down control necessary for successful STM and WM processes. Little is known regarding the spectral properties of the frontoparietal network during STM or WM processes in ASD, although certain neural frequencies have been linked to specific neural mechanisms.

METHODS

We analysed magnetoencephalographic data from 39 control adults (26 males; 27.15 ± 5.91 years old) and 40 adults with ASD (26 males; 27.17 ± 6.27 years old) during a 1-back condition (STM) of an n-back task, and from a subset of this sample during a 2-back condition (WM). We performed seed-based connectivity analyses using regions of the frontoparietal network. Interregional synchrony in theta, alpha, and beta bands was assessed with the phase difference derivative and compared between groups during periods of maintenance and recognition.

RESULTS

During maintenance of newly presented vs. repeated stimuli, the two groups did not differ significantly in theta, alpha, or beta phase synchrony for either condition. Adults with ASD showed alpha-band synchrony in a network containing the right dorsolateral prefrontal cortex, bilateral inferior parietal lobules (IPL), and precuneus in both 1- and 2-back tasks, whereas controls demonstrated alpha-band synchrony in a sparser set of regions, including the left insula and IPL, in only the 1-back task. During recognition of repeated vs. newly presented stimuli, adults with ASD exhibited decreased theta-band connectivity compared to controls in a network with hubs in the right inferior frontal gyrus and left IPL in the 1-back condition. Whilst there were no group differences in connectivity in the 2-back condition, adults with ASD showed no frontoparietal network recruitment during recognition, whilst controls activated networks in the theta and beta bands.

CONCLUSIONS

Our findings suggest that since adults with ASD performed well on the n-back task, their appropriate, but effortful recruitment of alpha-band mechanisms in the frontoparietal network to maintain items in STM and WM may compensate for atypical modulation of this network in the theta band to recognise previously presented items in STM.