Conceptualization of the latent structure of autism: further evidence and discussion of dimensional and hybrid models.

Autism spectrum disorder (ASD) might be conceptualized as an essentially dimensional, categorical, or hybrid model. Yet, current empirical studies are inconclusive and the latent structure of ASD has explicitly been examined only in a few studies. The aim of our study was to identify and discuss the latent model structure of behavioral symptoms related to ASD and to address the question of whether categories and/or dimensions best represent ASD symptoms. We included data of 2920 participants (1-72 years of age), evaluated with the Autism Diagnostic Observation Schedule (Modules 1-4). We applied latent class analysis, confirmatory factor analysis, and factor mixture modeling and evaluated the model fit by a combination of criteria. Based on the model selection criteria, the model fits, the interpretability as well as the clinical utility we conclude that the hybrid model serves best for conceptualization and assessment of ASD symptoms. It is both grounded in empirical evidence and in clinical usefulness, is in line with the current classification system (DSM-5) and has the potential of being more specific than the dimensional approach (decreasing false positive diagnoses).

[Diagnostic accuracy of the ADOS-2 taking account of gender effects]. / Zur Validität der deutschen Fassung der ADOS-2 unter Berücksichtigung von Geschlechtseffekten.

Objectives: The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) is a revision of the standardized assessment for individuals with suspected autism spectrum disorders (ASD). The study examines the diagnostic accuracy of the original and revised algorithms for Modules 1 through 3. Methods: In a large clinical sample of children and adolescents (N = 1080, age 1.7 to 20.5), the differentiation of ASD from relevant differential diagnoses was investigated. As studies on the diagnostic accuracy for girls are sparse, comparisons concerning the diagnostic accuracy for gender subgroups were undertaken. Results: The revised algorithms exhibit an improvement in sensitivity (84.9 %) and a slight reduction in specificity (85.7 %). The improvements in the ADOS-2 pertain especially to cases with core autism and girls. Including the repetitive behavior domain in the algorithm contributes to a correct clinical ASD classification in modules 2 and 3. This was not found for younger children examined with module 1. Results also suggest less effective diagnostic differentiation for children and adolescents with internalizing disorders and conduct disorder. Conclusions: Good diagnostic accuracy was found for children in the average range of cognitive abilities. Results suggest good diagnostic utility for the ADOS-2 in clinical settings, provided that thorough diagnostics are given by experienced examiners.

Differentiation of autism spectrum disorder and mood or anxiety disorder.

LAY ABSTRACT: Symptoms of mood and anxiety disorders overlap with symptoms of autism spectrum disorder, making the diagnostic process challenging. This study found that a combination of communicational deficits and unusual and/or inappropriate social overtures facilitates differentiation between autism spectrum disorder and mood and anxiety disorders. Furthermore, the results confirm the essential need of a behavioral observation with the Autism Diagnostic Observation Schedule in combination with a full Autism Diagnostic Interview-Revised to support diagnostic decisions.

An International Clinical Study of Ability and Disability in Autism Spectrum Disorder Using the WHO-ICF Framework.

This is the fourth international preparatory study designed to develop International Classification of Functioning, Disability and Health (ICF, and Children and Youth version, ICF-CY) Core Sets for Autism Spectrum Disorder (ASD). Examine functioning of individuals diagnosed with ASD as documented by the ICF-CY in a variety of clinical settings. A cross-sectional study was conducted, involving 11 units from 10 countries. Clinical investigators assessed functioning of 122 individuals with ASD using the ICF-CY checklist. In total, 139 ICF-CY categories were identified: 64 activities and participation, 40 body functions and 35 environmental factors. The study results reinforce the heterogeneity of ASD, as evidenced by the many functional and contextual domains impacting on ASD from a clinical perspective.