Background: The nosology of autism spectrum disorders (ASD) is at a critical point in history as the field seeks to better define dimensions of social‐communication deficits and ...restricted/repetitive behaviors on an individual level for both clinical and neurobiological purposes. These different dimensions also suggest an increasing need for quantitative measures that accurately map their differences, independent of developmental factors such as age, language level and IQ.
Method: Psychometric measures, clinical observation as well as genetic, neurobiological and physiological research from toddlers, children and adults with ASD are reviewed.
Results: The question of how to conceptualize ASDs along dimensions versus categories is discussed within the nosology of autism and the proposed changes to the DSM‐5 and ICD‐11. Differences across development are incorporated into the new classification frameworks.
Conclusions: It is crucial to balance the needs of clinical practice in ASD diagnostic systems, with neurobiologically based theories that address the associations between social‐communication and restricted/repetitive dimensions in individuals. Clarifying terminology, improving description of the core features of ASD and other dimensions that interact with them and providing more valid and reliable ways to quantify them, both for research and clinical purposes, will move forward both practice and science.
This article provides a selective review of advances in scientific knowledge about autism spectrum disorder (ASD), using DSM-5 (
Diagnostic and Statistical Manual of Mental Disorders
, fifth edition) ...diagnostic criteria as a framework for the discussion. We review literature that prompted changes to the organization of ASD symptoms and diagnostic subtypes in DSM-IV, and we examine the rationale for new DSM-5 specifiers, modifiers, and severity ratings as well as the introduction of the diagnosis of social (pragmatic) communication disorder. Our goal is to summarize and critically consider the contribution of clinical psychology research, along with that of other disciplines, to the current conceptualization of ASD.
Autism Diagnostic Observation Schedule (ADOS) Modules 1-3 item and domain total distributions were reviewed for 1,630 assessments of children aged 14 months to 16 years with an autism spectrum ...disorder (ASD) or with heterogeneous non-spectrum disorders. Children were divided by language level and age to yield more homogeneous cells. Items were chosen that best differentiated between diagnoses and were arranged into domains on the basis of multi-factor item-response analysis. Reflecting recent research, the revised algorithm now consists of two new domains, Social Affect and Restricted, Repetitive Behaviors (RRB), combined to one score to which thresholds are applied, resulting in generally improved predictive value.
Background: The Social Responsiveness Scale (SRS) is a parent‐completed screening questionnaire often used to measure autism spectrum disorders (ASD) severity. Although child characteristics are ...known to influence scores from other ASD‐symptom measures, as well as parent‐questionnaires more broadly, there has been limited consideration of how non‐ASD‐specific factors may affect interpretation of SRS scores. Previous studies have explored effects of behavior problems on SRS specificity, but have not addressed influences on the use of the SRS as a quantitative measure of ASD‐symptoms.
Method: Raw scores (SRS‐Raw) from parent‐completed SRS were analyzed for 2,368 probands with ASD and 1,913 unaffected siblings. Regression analyses were used to assess associations between SRS scores and demographic, language, cognitive, and behavior measures.
Results: For probands, higher SRS‐Raw were associated with greater non‐ASD behavior problems, higher age, and more impaired language and cognitive skills, as well as scores from other parent report measures of social development and ASD‐symptoms. For unaffected siblings, having more behavior problems predicted higher SRS‐Raw; male gender, younger age, and poorer adaptive social and expressive communication skills also showed small, but significant effects.
Conclusions: When using the SRS as a quantitative phenotype measure, the influence of behavior problems, age, and expressive language or cognitive level on scores must be considered. If effects of non‐ASD‐specific factors are not addressed, SRS scores are more appropriately interpreted as indicating general levels of impairment, than as severity of ASD‐specific symptoms or social impairment. Additional research is needed to consider how these factors influence the SRS’ sensitivity and specificity in large, clinical samples including individuals with disorders other than ASD.
Research on the identification and evaluation of autism spectrum disorders is reviewed, and best practices for clinical work are discussed. The latest research on diagnostic tools, and their ...recommended use, is also reviewed. Recommendations include the use of instruments designed to assess multiple domains of functioning and behavior, the inclusion of parents and caregivers as active partners, and the consideration of developmental factors throughout the diagnostic process.
For the first time, we use a longitudinal population-based autism cohort to chart the trajectories of cognition and autism symptoms from childhood to early adulthood and identify features that ...predict the level of function and change with development.
Latent growth curve models were fitted to data from the Special Needs and Autism Project cohort at three time points: 12, 16, and 23 years. Outcome measures were IQ and parent-reported Social Responsiveness Scale autism symptoms. Of the 158 participants with an autism spectrum disorder at 12 years, 126 (80%) were reassessed at 23 years. Child, family, and contextual characteristics obtained at 12 years predicted intercept and slope of the trajectories.
Both trajectories showed considerable variability. IQ increased significantly by a mean of 7.48 points from 12 to 23 years, whereas autism symptoms remained unchanged. In multivariate analysis, full-scale IQ was predicted by initial language level and school type (mainstream/specialist). Participants with a history of early language regression showed significantly greater IQ gains. Autism symptoms were predicted by Social Communication Questionnaire scores (lifetime version) and emotional and behavioral problems. Participants attending mainstream schools showed significantly fewer autism disorder symptoms at 23 years than those in specialist settings; this finding was robust to propensity score analysis for confounding.
Our findings suggest continued cognitive increments for many people with autism across the adolescent period, but a lack of improvement in autism symptoms. Our finding of school influences on autism symptoms requires replication in other cohorts and settings before drawing any implications for mechanisms or policy.
This single-blind, randomized, multisite, intent-to-treat study was designed to replicate and extend Dawson et al.'s (Pediatrics. 2010;125: e17-e23) randomized controlled trial testing the effects of ...the Early Start Denver Model (ESDM), an intensive play- and routines-based intervention delivered in natural settings.
A randomized controlled trial was conducted at 3 universities. One hundred eighteen children 14 to 24 months old with autism spectrum disorder were enrolled and randomly assigned to ESDM or community interventions for 27 months. Eighty-one children completed the full treatment course and all assessments; data from all 118 children were used in analyses. Children assigned to the ESDM intervention received 3 months of weekly parent coaching followed by 24 months of 15 hour per week (on average) 1:1 treatment weekly on average in homes or daycare settings from supervised therapy assistants while parents received coaching 4 hours monthly from a certified ESDM therapist.
For the primary analyses, there were time-by-group and time-by-group-by-site interactions for language outcome. In the significant 3-way interaction involving site, 2 sites showed a significant ESDM advantage and the third site showed no significant group differences. In the planned 2-way analysis that pooled data across all 3 sites, there was a significant advantage found for the ESDM group. For the secondary analyses, there were no significant differences between the ESDM and community groups involving developmental quotient, autism severity, or adaptive behavior. The treatment effect of group on language outcomes was not moderated by baseline developmental quotient, autism severity, or language.
Results of the primary analysis provide a partial replication of Dawson et al.'s 2010 language findings.
Intensive Intervention for Toddlers with Autism; https://clinicaltrials.gov/; NCT00698997.
Using data from a large-scale epidemiological sample (generously shared with us by the Norwegian Institute of Public Health), we provide initial examples of how and why such a stepped care and ...personalised health approach could be applied to address both the core features of autism and co-occurring conditions. Focused research strategies at the government or institutional level should be prioritised with an emphasis on clinical practice that can increase the understanding of what interventions work, for whom, when, how, with what general outcomes, and at what cost. Governments and services should monitor access to provision to ensure that underserved groups, including those who are minimally verbal, girls and women, minority ethnic groups, from socially disadvantaged backgrounds, or with severe co-occurring conditions, have equitable access to appropriate services. Societies in every part of the world have a duty of care to all people with autism and those who care for them, and investment in research and services needs to be targeted wisely to help them to reach better life outcomes and propel the change that makes this possible. Because it is defined by the intersection of social communication and sensory, restricted, and repetitive behaviours and interests, autism is a relatively specific disorder.
Autism Diagnostic Interview-Revised (Rutter et al. in Autism diagnostic interview-revised. Western Psychological Services, Los Angeles,
2003
) diagnostic algorithms specific to toddlers and young ...preschoolers were created using 829 assessments of children aged from 12 to 47 months with ASD, nonspectrum disorders, and typical development. The participants were divided into three more homogeneous groups by language level and age. Items that best differentiated the diagnostic groups were selected and arranged into domains based on multifactor item-response analyses. Using the new algorithms for toddlers and preschool children, we were able to improve sensitivity and specificity compared to the previously developed algorithm.
The heterogeneous clinical presentations of individuals with autism spectrum disorders (ASDs) poses a significant challenge for sample characterization and limits the interpretability and ...replicability of research studies. The Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) diagnostic criteria for ASD, with its dimensional approach, may be a useful framework to increase the homogeneity of research samples. In this review, we summarize the revisions to the diagnostic criteria for ASD, briefly highlight the literature supporting these changes, and illustrate how DSM-5 can improve sample characterization and provide opportunities for researchers to identify possible subtypes within ASD.
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