Quantitative autistic traits ascertained in a national survey of 22 529 Japanese schoolchildren

Abstract

Quantitative autistic traits ascertained in a national survey of 22 529 Japanese schoolchildren.Objective: Recent epidemiologic studies worldwide have documented a rise in prevalence rates for autism spectrum disorders (ASD). Broadening of diagnostic criteria for ASD may be a major contributor to the rise in prevalence, particularly if superimposed on an underlying continuous distribution of autistic traits. This study sought to determine the nature of the population distribution of autistic traits using a quantitative trait measure in a large national population sample of children. Method: The Japanese version of the Social Responsiveness Scale (SRS) was completed by parents on a nationally representative sample of 22 529 children, age 6-15. Results: Social Responsiveness Scale scores exhibited a skewed normal distribution in the Japanese population with a single-factor structure and no significant relation to IQ within the normal intellectual range. There was no evidence of a natural 'cutoff' that would differentiate populations of categorically affected children from unaffected children. Conclusion: This study provides evidence of the continuous nature of autistic symptoms measured by the SRS, a validated quantitative trait measure. The findings reveal how paradigms for diagnosis that rest on arbitrarily imposed categorical cutoffs can result in substantial variation in prevalence estimation, especially when measurements used for case assignment are not standardized for a given population. Significant outcomes• In a large Japanese child population, behaviorally measured autistic traits are continuously distributed without any apparent deflection in the distribution plot that would signal a natural cutoff for categorical diagnoses. This is similar to the distribution pattern in US and European samples.• Autistic traits measured quantitatively by parents differ slightly by culture, suggesting the need to interpret autism spectrum disorder (ASD) severity ratings with the use of culturally calibrated norms.• Many children who do not meet the diagnosis of ASD exhibit elevations in autistic traits measured quantitatively, suggesting the need to reconsider current diagnostic systems that assume discontinuity between affected and unaffected populations. Limitations• The response rate of this nationwide survey was 29%.• There is a possibility of bias that would differentiate respondents vs. non-respondents.• High-scoring children in the sample as a whole were not confirmed using diagnostic instruments, although quantitatively measured autistic traits were extensively clinically confirmed for a separate smaller sample.

Familiality of Quantitative Autism Traits

“…Moreover, contrary to the previous findings of Kamio and colleagues (11) in their nationwide study that included more than 20,000 school-aged children, we found no gender differences in the SRS scores of control children. This inconsistent finding may be the result of the limited size and homogeneity of our sample.…”

“…Reciprocal social behavior requires the individual to be cognizant of the emotional and interpersonal cues of others, to appropriately interpret and respond to those cues, and to be capable of emotional engagement (2). There is evidence that ASD traits are continuously distributed in the general population, genetically transmitted across generations, and aggregated at subclinical levels in relatives of individuals with autism (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). The phenotypic profile of subthreshold ASD traits that manifest in some relatives of autistic individuals has been referred to as the broader autistic phenotype (4); when measured by quantitative instruments, these broader deficits in social functioning are called quantitative autism traits (QAT) (13).…”

Cross-cultural differences in the Parent Rated Social Responsiveness Scale (SRS)? Evaluation of the Finnish version among high-functioning school aged males with and without autism spectrum disorder

“…Bö lte et al, 2008;Charman et al, 2007;Constantino & Gruber, 2005Kamio et al, 2012;Reiersen, Constantino, Volk, & Todd, 2007). Some findings in previous studies have, however, also shown possible over-identification in clinical samples (Aldridge, Gibbs, Schmidhofer, et al, 2012;Pine, Guyer, Goldwin, Towbin, & Leibenluft, 2008).…”

“…Constantino, Przybeck, Friesen, & Todd, 2000;Freitag, 2007;Kamio, Inada, Moriwaki, et al, 2012). In primary settings where a school aged child is referred to a health care provider (e.g., school nurse/psychologist/doctor) due to socio-emotional or neurocognitive problems, it can be challenging to identify children in need for more comprehensive assessment by a clinician specialized in ASD.…”

Propriedades psicométricas da Escala de Responsividade Social-2 para Transtornos do Espectro Autista

“…A ERS já foi extensamente traduzida em diversas culturas [6][7][8][9][10] . A ERS tem se mostrado um instrumento válido e confiável [6][7][8][9][10][11][12] , mas suas propriedades foram exploradas mais extensamente apenas segundo a Teoria Clássica dos Testes. A ERS não foi suficientemente explorada segundo a Teoria de Resposta ao Item ou de acordo com os modelos Rasch.…”