Examining the validity of autism spectrum disorder subtypes

Investigating the borders of autism spectrum disorder: lessons from the former diagnosis of pervasive developmental disorder not otherwise specified

Introduction

Autism Spectrum Disorder (ASD) diagnosis is relatively consensual in typical forms. The margins of the spectrum and their degree of extension, however, are controversial. This has far-reaching implications, which extend beyond theoretical considerations: first, peripheral forms of autism are more prevalent than central forms; second, we do not know how relevant typical-targeted recommendations are for atypical forms. In DSM-IV-TR, these margins of autism were studied within the category of Pervasive Developmental Disorder - Not Otherwise Specified (PDD-NOS). In spite of its low reliability, this former diagnosis was of particular interest to shed light on the gray area of margins. The aim of this systematic is therefore to investigate the clinical characteristics of PDD-NOS in comparison with Autistic Disorder.

Method

A stepwise systematic PRISMA literature review was conducted by searching PubMed and Web Of Science databases to select corresponding studies.

Results

The systematic review included 81 studies comprising 6,644 children with PDD-NOS. Cross-sectional and longitudinal studies comparing PDD-NOS and AD showed that PDD-NOS corresponds to milder form of autism with less impact and less associated disorder, with the exception of schizophrenia and mood disorder.

Discussion

Our review challenges initial views of PDD-NOS, and shows the clinical relevance of this diagnosis when dealing with the margins of autism, and the de facto diversity included in the spectrum. However, in view of the many limitations of PDD-NOS (low reliability, instability through time, low acceptability), we suggest taxonomic changes in DSM-5: we introduce a new category based on three main dimensions related to socialization impairment, emotional lability and psychotic symptoms.

Conclusion

Our review argues for a distinction between AD and PDD-NOS on clinical characteristics and thus highlights the need to study the margins of autism. While the limitations of the PDD-NOS category made it irrelevant to investigate these margins from a research perspective, we believe that a multidimensional approach for mental health professionals taping socialization, emotion lability and psychotic symptoms would be interesting. Our review therefore encourage future studies to test relevant criteria for a new category and possibly identify developmental trajectories, specific interventions and treatments.

Distinct Patterns of Cognitive Outcome in Young Children With Autism Spectrum Disorder Receiving the Early Start Denver Model

Evidence-based, early intervention significantly improves developmental outcome in young children with autism. Nonetheless, there is high interindividual heterogeneity in developmental trajectories during the therapy. It is established that starting intervention as early as possible results in better developmental outcomes. But except for younger age at start, there is no clear consensus about behavioral characteristics that could provide a reliable individual prediction of a child's developmental outcome after receiving an early intervention. In this study, we analyze developmental trajectories of preschoolers with autism who received 2 years of intervention using the Early Start Denver Model (ESDM) approach in Geneva, Switzerland in an individual setting (n = 55, aged 28.7 ± 5.1 months with a range of 15-42). Our aim was to identify early predictors of response to intervention. We applied a cluster analysis to distinguish between 3 groups based on their cognitive level at intake, and rates of cognitive change over the course of intervention. The first group of children only had a mild cognitive delay at intake and nearly no cognitive delay by the end of intervention (Higher Cognitive at baseline: HC). The children in the two other groups all presented with severe cognitive delay at baseline. However, they had two very different patterns of response to intervention. The majority significantly improved developmental scores over the course of intervention (Optimal Responders: OptR) whereas a minority of children showed only modest improvement (Minimal Responders: MinR). Further analyses showed that children who ended up having an optimal 2-year intervention outcome (OptR) were characterized by higher adaptive functioning at baseline combined with rapid developmental improvement during the first 6 months of intervention. Inversely, less significant progress by the sixth month of intervention was associated with a less optimal response to treatment (MinR).

Identification of Autism Subtypes Based on Wavelet Coherence of BOLD FMRI Signals Using Convolutional Neural Network

The functional connectivity (FC) patterns of resting-state functional magnetic resonance imaging (rs-fMRI) play an essential role in the development of autism spectrum disorders (ASD) classification models. There are available methods in literature that have used FC patterns as inputs for binary classification models, but the results barely reach an accuracy of 80%. Additionally, the generalizability across multiple sites of the models has not been investigated. Due to the lack of ASD subtypes identification model, the multi-class classification is proposed in the present study. This study aims to develop automated identification of autism spectrum disorder (ASD) subtypes using convolutional neural networks (CNN) using dynamic FC as its inputs. The rs-fMRI dataset used in this study consists of 144 individuals from 8 independent sites, labeled based on three ASD subtypes, namely autistic disorder (ASD), Asperger’s disorder (APD), and pervasive developmental disorder not otherwise specified (PDD-NOS). The blood-oxygen-level-dependent (BOLD) signals from 116 brain nodes of automated anatomical labeling (AAL) atlas are used, where the top-ranked node is determined based on one-way analysis of variance (ANOVA) of the power spectral density (PSD) values. Based on the statistical analysis of the PSD values of 3-level ASD and normal control (NC), putamen_R is obtained as the top-ranked node and used for the wavelet coherence computation. With good resolution in time and frequency domain, scalograms of wavelet coherence between the top-ranked node and the rest of the nodes are used as dynamic FC feature input to the convolutional neural networks (CNN). The dynamic FC patterns of wavelet coherence scalogram represent phase synchronization between the pairs of BOLD signals. Classification algorithms are developed using CNN and the wavelet coherence scalograms for binary and multi-class identification were trained and tested using cross-validation and leave-one-out techniques. Results of binary classification (ASD vs. NC) and multi-class classification (ASD vs. APD vs. PDD-NOS vs. NC) yielded, respectively, 89.8% accuracy and 82.1% macro-average accuracy, respectively. Findings from this study have illustrated the good potential of wavelet coherence technique in representing dynamic FC between brain nodes and open possibilities for its application in computer aided diagnosis of other neuropsychiatric disorders, such as depression or schizophrenia.

Interpretable Machine Learning Reveals Dissimilarities Between Subtypes of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a heterogeneous neuropsychiatric disorder with a complex genetic background. Analysis of altered molecular processes in ASD patients requires linear and nonlinear methods that provide interpretable solutions. Interpretable machine learning provides legible models that allow explaining biological mechanisms and support analysis of clinical subgroups. In this work, we investigated several case-control studies of gene expression measurements of ASD individuals. We constructed a rule-based learning model from three independent datasets that we further visualized as a nonlinear gene-gene co-predictive network. To find dissimilarities between ASD subtypes, we scrutinized a topological structure of the network and estimated a centrality distance. Our analysis revealed that autism is the most severe subtype of ASD, while pervasive developmental disorder-not otherwise specified and Asperger syndrome are closely related and milder ASD subtypes. Furthermore, we analyzed the most important ASD-related features that were described in terms of gene co-predictors. Among others, we found a strong co-predictive mechanism between EMC4 and TMEM30A, which may suggest a co-regulation between these genes. The present study demonstrates the potential of applying interpretable machine learning in bioinformatics analyses. Although the proposed methodology was designed for transcriptomics data, it can be applied to other omics disciplines.

Relationship Between Early Social-Emotional Behavior and Autism Spectrum Disorder: A High-Risk Sibling Study

Social-emotional behavior in autism spectrum disorder (ASD) was examined among high-risk (HR; siblings of children diagnosed with ASD) and low-risk (LR; no family history of ASD) toddlers. Caregivers completed the Infant-Toddler Social Emotional Assessment (ITSEA) at 18 months, and blind diagnostic assessment for ASD was conducted at 36 months. Results indicated impairment in social-emotional functioning among HR toddlers subsequently diagnosed with ASD compared to other HR and LR toddlers, such that ITSEA domains (Internalizing, Dysregulation, Competence) and subdomains predicted later ASD symptoms and diagnosis. Receiver operating curves of optimal ITSEA cutoffs ranged from 0.23 to 0.44 for sensitivity, and 0.74 to 0.89 for specificity. Although classification accuracy for ASD was limited, group differences highlight the importance of considering social-emotional development when assessing ASD risk.

Muscle dysmorphia: A systematic and meta-analytic review of the literature to assess diagnostic validity

OBJECTIVE

Although muscle dysmorphia (MD) is a new addition to DSM-5 as a specifier of body dysmorphic disorder (BDD), previous studies have treated MD as a stand-alone diagnosis. We aimed to assess the validity of MD as a stand-alone diagnosis via systematic and meta-analytic review of MD literature using both Robins and Guze criteria and additional criteria from Kendler.

METHOD

We performed a systematic search of ProQuest, PsycInfo, and PubMed databases for the period of January 1993 to October 2019 resulting in 40 papers to examine Robins and Guze's criteria (clinical picture) as well as those added by Kendler (antecedent validators; concurrent validators; predictive validators).

RESULTS

We identified two distinct symptomatic presentations of MD using cluster analysis, a behavioral type and cognitive/behavioral type. For examining the concurrent validators, quantitative meta-analyses differentiated MD populations from controls; however, results were inconclusive in delineating MD from existing disorders. For assessing antecedent and predictive validators, the symptomatic profiles, treatment response, and familial links for MD were similar to those for BDD and for eating disorders.

DISCUSSION

We found preliminary support for MD as a clinically valid presentation, but insufficient evidence to determine whether it is best categorized as a specifier of BDD or unique psychiatric condition.

Semantic Processing in Autism Spectrum Disorders Is Associated With the Timing of Language Acquisition: A Magnetoencephalographic Study

Individuals with autism show difficulties in using sentence context to identify the correct meaning of ambiguous words, such as homonyms. In this study, the brain basis of sentence context effects on word understanding during reading was examined in autism spectrum disorder (ASD) and typical development (TD) using magnetoencephalography. The correlates of a history of developmental language delay in ASD were also investigated. Event related field responses at early (150 ms after the onset of a final word) and N400 latencies are reported for three different types of sentence final words: dominant homonyms, subordinate homonyms, and unambiguous words. Clear evidence for semantic access was found at both early and conventional N400 latencies in both TD participants and individuals with ASD with no history of language delay. By contrast, modulation of evoked activity related to semantic access was weak and not significant at early latencies in individuals with ASD with a history of language delay. The reduced sensitivity to semantic context in individuals with ASD and language delay was accompanied by strong right hemisphere lateralization at early and N400 latencies; such strong activity was not observed in TD individuals and individuals with ASD without a history of language delay at either latency. These results provide new evidence and support for differential neural mechanisms underlying semantic processing in ASD, and indicate that delayed language acquisition in ASD is associated with different lateralization and processing of language.

Trajectories of emotional and behavioral problems from childhood to early adult life

LAY ABSTRACT

Although mental health problems are common in autism, relatively little is known about their stability and the factors that influence their persistence or change over the life-course. To address this, we use data from the Special Needs and Autism Project (SNAP) cohort studied at three time-points from 12 to 23 years. Using the parent-reported Strengths and Difficulties Questionnaire (SDQ) domains of conduct, emotional, and ADHD symptoms, we evaluated the role of child, family, and contextual characteristics on these three trajectories. Symptoms decreased significantly over time for all three domains, but many participants still scored above the published disorder cutoffs. Individuals showed high levels of persistence. Higher initial adaptive function and language levels predicted a greater decline in conduct and ADHD symptoms. In contrast, higher language functioning was associated with higher levels of emotional symptoms, as was lower levels of autism symptom severity and higher parental education. Those with higher neighborhood deprivation had higher initial conduct problems but a steeper decline over time. Our findings highlight that it may be possible to accurately predict mental health trajectories over this time period, which could help parents and carers in planning and help professionals target resources more efficiently.

Review of cluster analysis of phenotypic data in Autism Spectrum Disorders: distinct subtypes or a severity gradient model?

Background: Individuals with autism spectrum disorder (ASD) form a heterogeneous group, posing a challenge for clinical definition. Additional problems regarding the diverse clinical presentation arise from changes in diagnostic criteria according to the latest Diagnostic and Statistical Manual of Mental Disorders (DSM-5), with exclusion of individuals who met earlier criteria or inclusion of more than previously. Objectives: To investigate studies that have attempted to reduce the heterogeneity of ASD based on cluster analysis of phenotypic data and to clarify whether ASD should be interpreted as 'a unitary spectrum,' with a severity gradient, or defined by distinct subtypes. This will allow better understanding of the disorder with implications for its treatment and prognosis. Methods: A literature search was made through PubMed, Researchgate and Google Scholar for studies of ASD populations. In addition, reference lists from identified studies were reviewed. Results: Only 10 studies were found that dealt with the heterogeneity of ASD and its different subtypes, based on the review prerequisites. Most of the studies appear to support the existence of subtypes within ASD, but it remains unclear whether these are considered as different specific subtypes with characteristic profiles of symptoms or as a part of a severity gradient across symptom domains. Conclusions: Drawing definitive conclusions from the published studies about the nature of ASD is difficult, due to the fundamental methodological differences among the studies and their inconsistent findings. This review shed light on a number of discrepancies regarding the current classification of ASD. However, future research will be necessary to provide a more definite answer on the question of a definition based on separate diagnostic subtypes or on a severity gradient by including larger samples that are followed longitudinal and by applying better diagnostic system and choosing the appropriate variables.

Subtyping the Autism Spectrum Disorder: Comparison of Children with High Functioning Autism and Asperger Syndrome

Since Hans Asperger's first description (Arch Psych Nervenkrankh 117:76-136, 1944), through Lorna Wing's translation and definition (Psychol Med 11:115-129, 1981), to its introduction in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM, 1994), Asperger Syndrome has always aroused huge interest and debate, until vanishing in the DSM fifth edition (2013). The debate regarded its diagnostic validity and its differentiation from high functioning autism (HFA). The present study aimed to examine whether AS differed from HFA in clinical profiles and to analyze the impact of DSM-5's innovation. Differences in cognitive, language, school functioning and comorbidities, were revealed when 80 AS and 70 HFA patients (3-18 years) were compared. Results suggested that an AS empirical distinction within autism spectrum disorder should be clinically useful.

Identifying Needs-Based Groupings Among People Accessing Intellectual Disability Services

There is increasing emphasis on needs-led service provision for people with intellectual disability (ID). This study outlines the statistical cluster analysis of clinical data from 1,692 individuals accessing secondary care ID services in the United Kingdom (U.K.) Using objective needs assessment data from a newly developed ID assessment tool, six clusters were identified. These had clinical face validity and were validated using six concurrently (but independently) rated tools. In keeping with previous studies, the clusters varied in terms of overall level of need as well as specific clinical features (autism spectrum disorder, mental health problems, challenging behaviors and physical health conditions). More work is now needed to further develop these clusters and explore their utility for planning, commissioning and optimizing needs-led services.

The Prevalence of Autism Spectrum Disorders in Adult Psychiatric Inpatients: A Systematic Review

Background:

Whilst the prevalence of autism spectrum disorders in adults within the community setting is well-established, less is known about the prevalence among adults based within a psychiatric inpatient setting.

Objective:

To conduct a systematic literature review pertaining to the prevalence of autism spectrum disorders among the adult psychiatric inpatient population.

Method:

Eligibility criteria included: (a) investigation of the prevalence of autism spectrum disorders (b) adult psychiatric inpatient study population (c) published in English language. Electronic databases accessed included PubMed, Medline, CINAHL, PsycINFO and EMBASE. Additionally, the ancestry method was utilised for the references of eligible papers, as well as grey literature searches and consultation with experts in the field.

Results:

From the search, 4 studies were identified which satisfied the inclusion criteria, conducted in a variety of inpatient psychiatric settings, including secure forensic and intellectual disability units and a state psychiatric hospital. There were significant differences in methodological approaches, including the screening tests, diagnostic instruments and diagnostic criteria utilised. Autism spectrum disorder prevalence estimates varied considerably, from 2.4-9.9%.

Conclusion:

From the limited research data currently available, it appears that the prevalence of autism spectrum disorders is increased in inpatient psychiatric settings relative to the general population. There is a need for further high quality research in this patient group, to add to this limited evidence base, as well as in developing effective strategies to identify patients with a high likelihood of autism spectrum disorders within this setting.

Cluster analysis of autism spectrum disorder symptomatology: Qualitatively distinct subtypes or quantitative degrees of severity of a single disorder?

The decision to collapse several related disorders into a single diagnosis of Autism Spectrum Disorder (ASD) generated significant controversy and debate. There has been mixed evidence as to whether various ASD subtypes are qualitatively distinct or if they exist on a spectrum of symptom severity. The present study conducted a two-step cluster analysis of major ASD symptoms in a sample of 147 young males with ASD aged between 6yr and 18yr with IQ > 70. Results indicated that a two-cluster solution (high and low severity of ASD symptomatology) was reliable and valid. Further, the construct of challenging behaviour was not a necessary component of the two-cluster solution, verifying the new conceptualisation of ASD. Further replication of these findings with other subsets of individuals with ASD is needed.

What is the Relationship Between Autism Spectrum Disorders and Epilepsy?

The association of epilepsy and autism spectrum disorders (ASD) is best understood by examining the relationship between social cognition, nonsocial cognition, and epilepsy. The relationship between ASD and epilepsy is bidirectional and is strongly linked to intellectual disability (ID). The risk of developing ASD in children with epilepsy is highest in children with early onset seizures, with a high prevalence in children with infantile spasms. The risk of developing epilepsy in children first diagnosed with ASD is highest in those with ID. The prevalence of seizures in ASD increases with age. When epilepsy and ASD coexist, they share common pathophysiological mechanisms. In epilepsy with and without ID, social-cognitive deficits are an important determinant of neurodevelopmental outcomes. Early recognition of social deficits is an important aspect of the comprehensive management of children with epilepsy. Treating the seizures in individuals with epilepsy and ASD is crucial but interventions that address social-cognitive deficits are necessary to maximize neurodevelopmental outcomes.

The determinants of service complexity in children with intellectual disabilities

BACKGROUND

To date, little is known about the predictors of healthcare service utilisation in children with intellectual disability (ID). The aim of this study was to identify the factors associated with service complexity in children with ID in Ontario, Canada.

METHODS

The population of this cross-sectional study consisted of 330 children with ID ages 4 to 18 years who accessed mental health services from November of 2012 to June of 2016 in four agencies. All participants completed the interRAI Child and Youth Mental Health and Developmental Disability Assessment Instrument, which is a semi-structured clinician-rated assessment that covers a range of common issues in children with ID. The outcome of this study was a service complexity variable based on (1) mental health service utilisation including any services provided to the child and (2) the management involved in providing that care. Eight individual items were summed, resulting in a scale that ranged from 0 to 8. Scores were then dichotomised into two groups: a score of 0-2 identified children with a low service complexity and a score of 3 or higher identified children with a high service complexity.

RESULTS

After adjustment for other covariates, gender was not associated with service complexity. Children aged 11-14 years and children with autism spectrum disorder used over twofold higher levels of service complexity than children aged equal to or less than 10 years or children with other causes of ID. Moreover, victims of bullying, high scores on the family functioning scale or learning or communication disorder were associated with greater service complexity.

CONCLUSIONS

The findings of this study indicate that a variety of factors are related to service complexity ranged from children's nonclinical (age and experiences of bullying) to clinical (e.g. aggression, learning/communication problems and autism spectrum disorder) characteristics.

Do Adults with High Functioning Autism or Asperger Syndrome Differ in Empathy and Emotion Recognition?

The present study examined whether adults with high functioning autism (HFA) showed greater difficulties in (1) their self-reported ability to empathise with others and/or (2) their ability to read mental states in others’ eyes than adults with Asperger syndrome (AS). The Empathy Quotient (EQ) and ‘Reading the Mind in the Eyes’ Test (Eyes Test) were compared in 43 adults with AS and 43 adults with HFA. No significant difference was observed on EQ score between groups, while adults with AS performed significantly better on the Eyes Test than those with HFA. This suggests that adults with HFA may need more support, particularly in mentalizing and complex emotion recognition, and raises questions about the existence of subgroups within autism spectrum conditions.

Integrating care for neurodevelopmental disorders by unpacking control: A grounded theory study

BACKGROUND

To establish integrated healthcare pathways for patients with neurodevelopmental disorders (ND) such as autism spectrum disorder and attention-deficit hyperactivity disorder is challenging. This study sets out to investigate the main concerns for healthcare professionals when integrating ND care pathways and how they resolve these concerns.

METHODS

Using classic grounded theory (Glaser), we analysed efforts to improve and integrate an ND care pathway for children and youth in a Swedish region over a period of 6 years. Data from 42 individual interviews with a range of ND professionals, nine group interviews with healthcare teams, participant observation, a 2-day dialogue conference, focus group meetings, regional media coverage, and reports from other Swedish regional ND projects were analysed.

RESULTS

The main concern for participants was to deal with overwhelming ND complexity by unpacking control, which is control over strategies to define patients' status and needs. Unpacking control is key to the professionals' strivings to expand constructive life space for patients, to squeeze health care to reach available care goals, to promote professional ideologies, and to uphold workplace integrity. Control-seeking behaviour in relation to ND unpacking is ubiquitous and complicates integration of ND care pathways.

CONCLUSIONS

The Unpacking control theory expands central aspects of professions theory and may help to improve ND care development.

Attention Deficits in Children With Combined Autism and ADHD: A CPT Study

OBJECTIVE

To investigate characteristics of attention in children with the combination of autism spectrum disorder (ASD) and ADHD.

METHOD

Four groups of 8- to 10-year-old children were compared on the Conners' Continuous Performance Test-Second Edition (CCPT-II): (a) ASD + ADHD (n = 11), (b) ASD only (n = 9), (c) ADHD only (n = 38), and (d) no diagnosis (n = 134).

RESULTS

There was an overall effect of group on the Continuous Performance Test (CPT) index and measures of hit reaction time, accuracy, response style, variability, and consistency. The ASD + ADHD group, much like the ADHD only group, had a more risky response style, a higher variability, and a lower consistency than the ASD only group. The impact of intellectual function on CCPT-II performance was considerable in children within the ASD subgroups.

CONCLUSION

The findings underscore the importance of including measures of attention and intellectual function when assessing children with the combination of ASD and ADHD.

Reasoning on the Autism Spectrum: A Dual Process Theory Account

Dual process theory proposes two distinct reasoning processes in humans, an intuitive style that is rapid and automatic and a deliberative style that is more effortful. However, no study to date has specifically examined these reasoning styles in relation to the autism spectrum. The present studies investigated deliberative and intuitive reasoning profiles in: (1) a non-clinical sample from the general population with varying degrees of autism traits (n = 95), and (2) males diagnosed with ASD (n = 17) versus comparisons (n = 18). Taken together, the results suggest reasoning on the autism spectrum is compatible with the processes proposed by Dual Process Theory and that higher autism traits and ASD are characterised by a consistent bias towards deliberative reasoning (and potentially away from intuition).

Neuroanatomy of Individual Differences in Language in Adult Males with Autism

One potential source of heterogeneity within autism spectrum conditions (ASC) is language development and ability. In 80 high-functioning male adults with ASC, we tested if variations in developmental and current structural language are associated with current neuroanatomy. Groups with and without language delay differed behaviorally in early social reciprocity, current language, but not current autistic features. Language delay was associated with larger total gray matter (GM) volume, smaller relative volume at bilateral insula, ventral basal ganglia, and right superior, middle, and polar temporal structures, and larger relative volume at pons and medulla oblongata in adulthood. Despite this heterogeneity, those with and without language delay showed significant commonality in morphometric features when contrasted with matched neurotypical individuals (n = 57). In ASC, better current language was associated with increased GM volume in bilateral temporal pole, superior temporal regions, dorsolateral fronto-parietal and cerebellar structures, and increased white matter volume in distributed frontal and insular regions. Furthermore, current language-neuroanatomy correlation patterns were similar across subgroups with or without language delay. High-functioning adult males with ASC show neuroanatomical variations associated with both developmental and current language characteristics. This underscores the importance of including both developmental and current language as specifiers for ASC, to help clarify heterogeneity.

Which terms should be used to describe autism? Perspectives from the UK autism community

Recent public discussions suggest that there is much disagreement about the way autism is and should be described. This study sought to elicit the views and preferences of UK autism community members – autistic people, parents and their broader support network – about the terms they use to describe autism. In all, 3470 UK residents responded to an online survey on their preferred ways of describing autism and their rationale for such preferences. The results clearly show that people use many terms to describe autism. The most highly endorsed terms were ‘autism’ and ‘on the autism spectrum’, and to a lesser extent, ‘autism spectrum disorder’, for which there was consensus across community groups. The groups disagreed, however, on the use of several terms. The term ‘autistic’ was endorsed by a large percentage of autistic adults, family members/friends and parents but by considerably fewer professionals; ‘person with autism’ was endorsed by almost half of professionals but by fewer autistic adults and parents. Qualitative analysis of an open-ended question revealed the reasons underlying respondents’ preferences. These findings demonstrate that there is no single way of describing autism that is universally accepted and preferred by the UK’s autism community and that some disagreements appear deeply entrenched.

Youth with autism spectrum disorder comprehend lexicalized and novel primary conceptual metaphors

Individuals with autism spectrum disorder (ASD) have difficulty comprehending metaphors. However, no study to date has examined whether or not they understand conceptual metaphors (i.e. mappings between conceptual structures), which could be the building blocks of metaphoric thinking and understanding. We investigated whether 13 participants with ASD (age 7;03-22;03) and 13 age-matched typically developing (TD) controls could comprehend lexicalized conceptual metaphors (e.g., Susan is a warm person) and novel ones (e.g., Susan is a toasty person). Individuals with ASD performed at greater than chance levels on both metaphor types, although their performance was lower than TD participants. We discuss the theoretical relevance of these findings and educational implications.

The psychometric properties of the Quantitative-Checklist for Autism in Toddlers (Q-CHAT) as a measure of autistic traits in a community sample of Singaporean infants and toddlers

Background

There is growing research evidence that subclinical autistic traits are elevated in relatives of individuals with autism spectrum disorder (ASD), continuously distributed in the general population and likely to share common etiology with ASD. A number of measures have been developed to assess autistic traits quantitatively in unselected samples. So far, the Quantitative-Checklist for Autism in Toddlers (Q-CHAT) is one of very few measures developed for use with toddlers as young as 18 months, but little is known about its measurement properties and factor structure.

Methods

The present study examined internal consistency, factor structure, test-retest stability, and convergent validity of the Q-CHAT in a sample of toddlers in Singapore whose caregivers completed the Q-CHAT at 18 (n = 368) and 24 months (n = 396).

Results

Three factors were derived accounting for 38.1 % of the variance: social/communication traits, non-social/behavioral traits, and a speech/language factor. Internal consistency was suboptimal for the total and speech/language scores, but acceptable for the social/communication and non-social/behavioral factor scores. Scores were generally stable between 18 and 24 months. Convergent validity was found with the Pervasive Developmental Disorders subscale of the Child Behavior Checklist (CBCL) completed by caregivers when their children were 24 months. Q-CHAT total scores in this sample were higher than those reported in other unselected samples from the UK.

Conclusions

The Q-CHAT was found to have a three-factor structure, acceptable internal consistency for its two main factor scores (social/communication and non-social/behavioral), normally distributed scores in an unselected sample, and similar structure and measurement properties as those reported in other published studies. Findings are discussed in relation to existing literature and future directions for the validation of the Q-CHAT.

Promoting Shared Decision Making to strengthen outcome of young children with Autism Spectrum Disorders: the role of staff competence

Little is known on how the conceptual description of Shared Decision Making (SDM) accomplishes clinical practice in the context of lifetime disabilities as in particular Autism Spectrum Disorders (ASD), when intervention is long-lasting and requires constant family involvement. This study aimed mainly to investigate to what extent the staff's competence in SDM contributes to positive child and parent improvement when involving parents in Early Intensive Behavior Interventions (EIBI). It was also geared to verify whether SDM staff competence contributes to a child's treatment responsiveness. A total of 25 young children with ASD (23 male, 3 female, age range 34-92 months, mean age 51.4±13.6) were included in the study. Of these, nine children were allocated to a Parent Involvement condition accompanied by SDM Staff Training (PI-SDM), and eight children to a Parent Inclusion in Treatment Delivery Only condition without SDM Staff Training (PI-DO). Nine months treatment outcomes of severity, developmental and adaptive measures were compared to Treatment As Usual (n=8). PI-SDM was associated with improvement of autistic symptoms (p≤.05), adaptive functioning (p≤.01) and developmental outcome (p≤.01), as well as parent (p≤.05) and staff competence (p≤.001). The magnitude of outcome was inferior in the PI-PO and TAU group. A Reliable Change was identified in more than 40% of children included in PI-SDM, while PI-PO (>20%) and TAU (>12%) let to little Reliable Change and partially skill deterioration. Staff's SDM skill competence predicts reduced parental stress (β=-.500, p≤.05) and contributes significantly to a positive treatment responder trajectory (p≤.01), besides lower severity (p≤.05), higher adaptive (p≤.01) and communication skills (p≤.05). The study indicates that parent inclusion should be conceptualized as a collaborative partnership model rather than as adherence in treatment provision, based on a target SDM staff training that may constitute an external contributor to treatment responsiveness and positive child as well as parent outcome.

DSM-5 ASD moves forward into the past

The fifth edition of the diagnostic and statistical manual of mental disorders (DSM-5) (APA in diagnostic and statistical manual of mental disorders, Author, Washington, 2013) has decided to merge the subtypes of pervasive developmental disorders into a single category of autism spectrum disorder (ASD) on the assumption that they cannot be reliably differentiated from one another. The purpose of this review is to analyze the basis of this assumption by examining the comparative studies between Asperger's disorder (AsD) and autistic disorder (AD), and between pervasive developmental disorder not otherwise specified (PDDNOS) and AD. In all, 125 studies compared AsD with AD. Of these, 30 studies concluded that AsD and AD were similar conditions while 95 studies found quantitative and qualitative differences between them. Likewise, 37 studies compared PDDNOS with AD. Nine of these concluded that PDDNOS did not differ significantly from AD while 28 reported quantitative and qualitative differences between them. Taken together, these findings do not support the conceptualization of AD, AsD and PDDNOS as a single category of ASD. Irrespective of the changes proposed by the DSM-5, future research and clinical practice will continue to find ways to meaningfully subtype the ASD.

Parental mediation of television viewing and videogaming of adolescents with autism spectrum disorder and their siblings

Adolescents with autism spectrum disorder spend considerable time in media activities. Parents play an important role in shaping adolescents’ responses to media. This study explored the mediation strategies that parents of adolescents with autism spectrum disorder used to manage television and video game use, factors associated with their use of different strategies, and whether mediation strategies changed over time. A secondary purpose was to examine whether parents applied different mediation strategies to adolescents with autism spectrum disorder versus siblings, and the factors that created stress related to managing media use. Parents of 29 adolescents with autism spectrum disorder and 16 siblings completed questionnaires at two time points. Parents most frequently supervised their television viewing by watching it with the adolescents, and used restrictive strategies to regulate their videogaming. Parents used similar strategies for siblings, but more frequently applied restrictive and instructive strategies for videogaming with adolescents with autism spectrum disorder than their siblings. Restrictive mediation of television viewing for the adolescents decreased significantly over the year. Adolescents’ time spent in media activities, age, and behavior problems, and parents’ concerns about media use were significant factors associated with the strategies that parents employed. Parents’ stress related to the adolescents’ behavioral and emotional responses to parental restrictions.

Redefining autism spectrum disorder using DSM-5: the implications of the proposed DSM-5 criteria for autism spectrum disorders

A number of changes were made to pervasive developmental disorders (PDDs) in the recently released diagnostic and statistical manual of mental disorders (APA, Diagnostic and statistical manual of mental disorders, American Psychiatric Publishing, Arlington, VA, 2013). Of the 210 participants in the present study who met DSM-IV-TR criteria for a PDD [i.e., autistic disorder, Asperger's disorder and pervasive developmental disorder-not otherwise specified (PDD-NOS)], only 57.1% met DSM-5 criteria (specificity = 1.0) for autism spectrum disorder when criteria were applied concurrently during diagnostic assessment. High-functioning individuals (i.e., Asperger's disorder and PDD-NOS) were less likely to meet DSM-5 criteria than those with autistic disorder. A failure to satisfy all three criteria in the social-communication domain was the most common reason for exclusion (39%). The implications of these results are discussed.

Asperger's disorder will be back

This review focuses on identifying up-to-date number of publications that compared DSM-IV/ICD-10 Asperger's disorder (AspD) to Autistic Disorder/High-functioning Autism (AD/HFA). One hundred and twenty-eight publications were identified through an extensive search of major electronic databases and journals. Based on more than 90 clinical variables been investigated, 94 publications concluded that there were statistically significant or near significant level of quantitative and/or qualitative differences between AspD and AD/HFA groups; 4 publications found both similarities and differences between the two groups; 30 publications concluded with no differences between the two groups. Although DSM-5 ASD will eliminate Asperger's disorder. However, it is plausible to predict that the field of ASD would run full circle during the next decade or two and that AspD will be back in the next edition of DSM.

Increased risk of autism spectrum disorders at short and long interpregnancy intervals in Finland

OBJECTIVE

Both short and long interpregnancy intervals (IPI) are believed to present possible adverse conditions for fetal development. Short IPI has recently been associated with increased risk of autism, but whether long IPI increases risk for autism spectrum disorders (ASD) has not been thoroughly investigated. We investigated the association between short and long IPI in a Finnish population-based study.

METHOD

This study was conducted in the Finnish Prenatal Study of Autism, which is based in a national birth cohort. Children born in Finland in 1987 to 2005 and diagnosed with ASD by 2007 were identified through the Finnish Hospital Discharge Register. A total of 2,208 non-firstborn patients with ASD and 5,163 matched controls identified from the Finnish Medical Birth Register were included in the primary analysis. The association between IPI and ASD was determined using conditional logistic regression and adjusted for potential confounders.

RESULTS

Relative to births with an IPI of 24 to 59 months, those with the shortest IPI (<12 months) had an increased risk of ASD (odds ratio [OR] = 1.50, 95% CI = 1.28, 1.74) in confounder-adjusted models, whereas the ORs for longer IPI births (60-119 months and ≥120 months) were 1.28 (95% CI = 1.08, 1.52) and 1.44 (95% CI = 1.12, 1.85), respectively.

CONCLUSION

This study provides evidence that risk of ASD is increased at long as well as short IPI.

The neuropsychology of male adults with high-functioning autism or asperger syndrome

Autism Spectrum Disorder (ASD) is diagnosed on the basis of behavioral symptoms, but cognitive abilities may also be useful in characterizing individuals with ASD. One hundred seventy-eight high-functioning male adults, half with ASD and half without, completed tasks assessing IQ, a broad range of cognitive skills, and autistic and comorbid symptomatology. The aims of the study were, first, to determine whether significant differences existed between cases and controls on cognitive tasks, and whether cognitive profiles, derived using a multivariate classification method with data from multiple cognitive tasks, could distinguish between the two groups. Second, to establish whether cognitive skill level was correlated with degree of autistic symptom severity, and third, whether cognitive skill level was correlated with degree of comorbid psychopathology. Fourth, cognitive characteristics of individuals with Asperger Syndrome (AS) and high-functioning autism (HFA) were compared. After controlling for IQ, ASD and control groups scored significantly differently on tasks of social cognition, motor performance, and executive function (P's < 0.05). To investigate cognitive profiles, 12 variables were entered into a support vector machine (SVM), which achieved good classification accuracy (81%) at a level significantly better than chance (P < 0.0001). After correcting for multiple correlations, there were no significant associations between cognitive performance and severity of either autistic or comorbid symptomatology. There were no significant differences between AS and HFA groups on the cognitive tasks. Cognitive classification models could be a useful aid to the diagnostic process when used in conjunction with other data sources—including clinical history. Autism Res2014, 7: 568–581. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

Prevalence of Asperger syndrome among patients of an Early Intervention in Psychosis team

BACKGROUND

There is a lack of systematic studies into comorbidity of Asperger syndrome and psychosis.

AIM

To determine the prevalence of Asperger syndrome among patients of an early intervention in psychosis service.

METHODS

This study was a cross-sectional survey consisting of three phases: screening, case note review and diagnostic interviews. All patients on caseload (n = 197) were screened using the Autism Spectrum Disorder in Adults Screening Questionnaire. The case notes of patients screened positive were then reviewed for information relevant to Asperger syndrome. Those suspected of having Asperger syndrome were invited for a diagnostic interview.

RESULTS

Thirty patients were screened positive. Three of them already had a diagnosis of Asperger syndrome made by child and adolescent mental health services. After case note review, 13 patients were invited to interview. Four did not take part, so nine were interviewed. At interview, four were diagnosed with Asperger syndrome. In total, seven patients had Asperger syndrome. Thus, the prevalence rate in this population is at least 3.6%.

CONCLUSIONS

The results suggest that the prevalence of Asperger syndrome in first-episode psychosis is considerably higher than that in the general population. Clinicians working in early intervention teams need to be alert to the possibility of Asperger syndrome when assessing patients.

Empirically based phenotypic profiles of children with pervasive developmental disorders: interpretation in the light of the DSM-5

This study aimed to contribute to the Diagnostic and Statistical Manual (DSM) debates on the conceptualization of autism by investigating (1) whether empirically based distinct phenotypic profiles could be distinguished within a sample of mainly cognitively able children with pervasive developmental disorder (PDD), and (2) how profiles related to diagnoses and co-occurring behavioral and emotional problems. Six classes with distinct profiles were discerned. Three classes showed profiles not completely in line with the proposed DSM-5 conceptualization of autism. These classes included relatively many cognitively able individuals with PDD-not otherwise specified. However, profiles seemed to suit other diagnostic categories, such as social communication disorder. These alternative diagnoses could retain eligibility for services, and might adequately fit more specifically targeted interventions.

Variation by diagnostic subtype in risk for autism spectrum disorders associated with maternal parity among Finnish births

BACKGROUND

Associations between maternal parity and outcomes in offspring may provide evidence for involvement of prenatal exposures. The objective of this study was to determine whether risk for autism spectrum disorders (ASD) is associated with maternal parity.

METHODS

Diagnoses of childhood autism, Asperger syndrome, and pervasive developmental disorder, not otherwise specified (PDD-NOS) were examined separately and as a group. The study was conducted in the Finnish Prenatal Study of Autism, which is based in a national birth cohort. Children born in Finland in 1987-2005 and diagnosed with ASD by 2007 were identified through the Finnish Hospital Discharge Register. Four matched controls were selected for each case using the Finnish Medical Birth Register. The association between parity and each ASD was determined using conditional logistic regression and adjusted for number of children in the sibship and other potential confounders.

RESULTS

ASDs combined showed a pattern of decreasing risk with increasing parity (odds ratio OR for fourth or greater vs. first-born children, 0.43 [95% confidence interval (CI): 0.35, 0.51]). For childhood autism, an adjusted OR of 1.51 [95% CI 1.27, 1.81] was observed for second vs. first-born children. Associations for Asperger syndrome and PDD-NOS were consistent with those for all ASDs.

CONCLUSIONS

Differences in patterns of association between maternal parity and ASD subtypes may indicate varying contributions of specific environmental factors to risk; however, differences in diagnosis or in treatment seeking for childhood behavioural problems cannot be ruled out, particularly for higher functioning cases.

Autism in flux: a history of the concept from Leo Kanner to DSM-5

In this paper, I argue that a new relation between past and present - a supposed historical continuity in the meaning of autism - is created by the histories written by the discipline itself. In histories of autism written by 'practitioner-historians', a sense of scientific progress and an essentialist understanding of autism legitimize and reinforce current understandings and research directions in the field of autism. Conceptual discontinuities and earlier complexities and disputes concerning classifying and delineating autism are usually left out of the positivist narrative of autism. In an alternative history of the concept of autism, I demonstrate that there have been major shifts in the type of symptoms, signs and impairments that were - and are - thought to be essential and specific for autism.

Social anxiety predicts aggression in children with ASD: clinical comparisons with socially anxious and oppositional youth

The present study examined the degree to which social anxiety predicts aggression in children with high functioning autism spectrum disorders (HFASD, n = 20) compared to children with Social Anxiety Disorder (SAD, n = 20) or with Oppositional Defiant Disorder or Conduct Disorder (ODD/CD, n = 20). As predicted, children with HFASD reported levels of humiliation/rejection fears commensurate with children with SAD and exhibited aggression at levels commensurate with ODD/CD, and a curvilinear relationship between social fears and aggression was found in the HFASD group only. Results indicate the possibility of an optimal level of social-evaluative fears that is unique for children with HFASD; too little social fear or too much may contribute to problems with aggression.

Narrowly versus broadly defined autism spectrum disorders: differences in pre- and perinatal risk factors

This study examined the differential contribution of pre- and perinatal risks in narrowly versus broadly defined autism spectrum disorder (ASD) and across core symptom domains, IQ and co-morbid problems. Children with a DSM-IV diagnosis of autistic disorder (AD) (n = 121) or pervasive developmental disorder not otherwise specified (PDD-NOS) (n = 75) were compared to a typical control sample (n = 311). Diagnoses were based on extensive assessments between 12 and 49 months of age (M = 33.3, SD = 6.4) and re-evaluated at 43-98 months (M = 68.1, SD = 10.7) in 70% of the cases. Compared with controls, cases with ASD were more likely to be firstborn and show a suboptimal condition after birth. Case mothers reported more infections and more stress during pregnancy. Although the ASD subgroups showed mostly overlapping risks, cases with PDD-NOS differed from those with AD by higher exposure to smoking during pregnancy (SDP) and by a negative association of smoking with IQ, regardless of confounders. SDP appears to contribute more to broadly defined (PDD-NOS) than to narrowly defined ASD (AD). Findings suggest differences in etiological contributors between ASD phenotypes.

On the application of quantitative EEG for characterizing autistic brain: a systematic review

Autism-Spectrum Disorders (ASD) are thought to be associated with abnormalities in neural connectivity at both the global and local levels. Quantitative electroencephalography (QEEG) is a non-invasive technique that allows a highly precise measurement of brain function and connectivity. This review encompasses the key findings of QEEG application in subjects with ASD, in order to assess the relevance of this approach in characterizing brain function and clustering phenotypes. QEEG studies evaluating both the spontaneous brain activity and brain signals under controlled experimental stimuli were examined. Despite conflicting results, literature analysis suggests that QEEG features are sensitive to modification in neuronal regulation dysfunction which characterize autistic brain. QEEG may therefore help in detecting regions of altered brain function and connectivity abnormalities, in linking behavior with brain activity, and subgrouping affected individuals within the wide heterogeneity of ASD. The use of advanced techniques for the increase of the specificity and of spatial localization could allow finding distinctive patterns of QEEG abnormalities in ASD subjects, paving the way for the development of tailored intervention strategies.

Does a claims diagnosis of autism mean a true case?

The purpose of this study was to validate autism spectrum disorder cases identified through claims-based case identification algorithms against a clinical review of medical charts. Charts were reviewed for 432 children who fell into one of the three following groups: (a) more than or equal to two claims with an autism spectrum disorder diagnosis code (n = 182), (b) one claim with an autism spectrum disorder diagnosis code (n = 190), and (c) those who had no claims for autism spectrum disorder but had claims for other developmental or neurological conditions (n = 60). The algorithm-based diagnoses were compared with documented autism spectrum disorders in the medical charts. The algorithm requiring more than or equal to two claims for autism spectrum disorder generated a positive predictive value of 87.4%, which suggests that such an algorithm is a valid means to identify true autism spectrum disorder cases in claims data.

Subgrouping the autism "spectrum": reflections on DSM-5

DSM-5 has moved autism from the level of subgroups ("apples and oranges") to the prototypical level ("fruit"). But making progress in research, and ultimately improving clinical practice, will require identifying subgroups within the autism spectrum.

Predicting the academic achievement of gifted students with autism spectrum disorder

We are not well informed regarding the ability-achievement relationship for twice-exceptional individuals (very high cognitive ability and a diagnosed disability, e.g., autism spectrum disorder [ASD]). The research question for this investigation (N = 59) focused on the predictability of achievement among variables related to ability and education in a twice-exceptional sample of students (cognitive ability of 120 [91st percentile], or above, and diagnosed with ASD). We determined that WISC-IV Working Memory and Processing Speed Indices were both significantly positively correlated with achievement in math, reading, and written language. WISC Perceptual Reasoning Index was uniquely predictive of Oral Language test scores. Unexpected findings were that ASD diagnosis, Verbal Comprehension Index, and forms of academic acceleration were not related to the dependent variables.

Autism spectrum disorders

The revision of the diagnostic criteria for ASD has been widely anticipated and is expected to be an important contribution to the refinement of the definition of ASD. In the upcoming DSM-5, several changes have been made compared to the previous diagnostic criteria. They include no emphasis on language delay and age of onset except that ASD is defined as a neurodevelopmental disorder with symptoms in early childhood although the disorder may first be diagnosed later in life. The three areas of impairments in ASD are reduced to two areas, namely a social-communication domain and a behavioral domain including fixated interests and repetitive behaviors. In addition, the clinical presentation of ASD in the individual is described in more detail in terms of clinical specifiers. In addition to reporting these changes in the classification, the major international guidelines are introduced and a brief description of good clinical practice of assessment and the overall principles of intervention is provided.

Investigating phenotypic heterogeneity in children with autism spectrum disorder: a factor mixture modeling approach

BACKGROUND

Autism spectrum disorder (ASD) is characterized by notable phenotypic heterogeneity, which is often viewed as an obstacle to the study of its etiology, diagnosis, treatment, and prognosis. On the basis of empirical evidence, instead of three binary categories, the upcoming edition of the DSM 5 will use two dimensions - social communication deficits (SCD) and fixated interests and repetitive behaviors (FIRB) - for the ASD diagnostic criteria. Building on this proposed DSM 5 model, it would be useful to consider whether empirical data on the SCD and FIRB dimensions can be used within the novel methodological framework of Factor Mixture Modeling (FMM) to stratify children with ASD into more homogeneous subgroups.

METHODS

The study sample consisted of 391 newly diagnosed children (mean age 38.3 months; 330 males) with ASD. To derive subgroups, data from the Autism Diagnostic Interview-Revised indexing SCD and FIRB were used in FMM; FMM allows the examination of continuous dimensions and latent classes (i.e., categories) using both factor analysis (FA) and latent class analysis (LCA) as part of a single analytic framework.

RESULTS

Competing LCA, FA, and FMM models were fit to the data. On the basis of a set of goodness-of-fit criteria, a 'two-factor/three-class' factor mixture model provided the overall best fit to the data. This model describes ASD using three subgroups/classes (Class 1: 34%, Class 2: 10%, Class 3: 56% of the sample) based on differential severity gradients on the SCD and FIRB symptom dimensions. In addition to having different symptom severity levels, children from these subgroups were diagnosed at different ages and were functioning at different adaptive, language, and cognitive levels.

CONCLUSIONS

Study findings suggest that the two symptom dimensions of SCD and FIRB proposed for the DSM 5 can be used in FMM to stratify children with ASD empirically into three relatively homogeneous subgroups.

Mindfulness-based therapy in adults with an autism spectrum disorder: a randomized controlled trial

Research shows that depression and anxiety disorders are the most common psychiatric concern in autism spectrum disorders (ASD). Mindfulness-based therapy (MBT) has been found effective in reducing anxiety and depression symptoms, however research in autism is limited. Therefore, we examined the effects of a modified MBT protocol (MBT-AS) in high-functioning adults with ASD. 42 participants were randomized into a 9-week MBT-AS training or a wait-list control group. Results showed a significant reduction in depression, anxiety and rumination in the intervention group, as opposed to the control group. Furthermore, positive affect increased in the intervention group, but not in the control group. Concluding, the present study is the first controlled trial to demonstrate that adults with ASD can benefit from MBT-AS.

Life Satisfaction of Neurotypical Women in Intimate Relationship with an Asperger's Syndrome Partner: A Systematic Review of the Literature

This systematic review explores the psychosocial wellbeing of neurotypical (NT) women in intimate relationship with persons with Asperger's Syndrome (AS), and intervention models for such relationships. Over 20 pertinent scholarly databases were searched in April 2011. The initial search yielded 1,736 unique items. Articles were eligible if they were a peer-reviewed journal article or a peer-reviewed thesis investigating adult couple relationships where only one partner had AS. Ten studies were agreed by both reviewers to have met these final inclusion criteria. Utilising the National Health and Medical Research Council (NHMRC) guidelines the body of evidence comprising the final 10 studies was assessed to be of an overall grade D or ‘weak’. None of the studies included for final analyses were intervention studies.