ASD symptoms in toddlers and preschoolers: An examination of sex differences

Abstract

Although considerable work has documented higher prevalence rates of autism spectrum disorder (ASD) in boys, fewer studies have focused on sex differences within samples of young children at‐risk for ASD. This study examined sex differences in ASD symptom domains and ASD screening outcomes among toddlers (18–35 months) and preschoolers (36–72 months) with ASD‐related concerns. Participants included 480 children between 18 and 72 months evaluated by university‐based ASD specialty clinics. Results revealed significant sex differences in severity of social communication (SC) deficits across age groups. Within the toddler group, girls diagnosed with ASD displayed greater SC deficits according to standardized observation and clinician severity ratings. Within the preschool group, girls diagnosed with ASD were rated by parents as having more severe SC deficits, but these differences were not corroborated by standardized observations or clinician ratings. No sex differences emerged for severity of restricted repetitive behaviors (RRBs) for either age group. Across the entire referred sample, boys and girls did not differ in terms of scores on commonly used screening instruments. Importantly, results suggest that two of the most commonly used ASD screeners (i.e., Modified‐Checklist for Autism in Toddlers‐Revised with Follow‐up and Social Communication Questionnaire ) may underidentify RRBs in toddler and preschool‐aged girls as screening scores were only influenced by severity of SC deficits. Greater SC deficits in young girls with ASD along with its impact on screening status suggests greater attention be placed on the under‐identification of ASD in girls as well as current screening measures' ability to tap into the topography of ASD symptoms across genders. Autism Res 2020, 13: 157–166. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryIn this study, we found that young girls diagnosed with autism spectrum disorder tend to have greater social communication deficits than young boys and that these differences vary by age. Specifically, toddler‐aged girls receive higher clinician ratings of social communication deficits when compared to boys, while preschool‐aged girls receive higher parent ratings of social communication deficits. For girls, current screening tools seem to be more highly influenced by severity of social communication deficits than by restricted repetitive behaviors.

Sex Differences in Autism Spectrum Disorder: Diagnostic, Neurobiological, and Behavioral Features

“…Additionally, despite the fact that the tools and techniques for assessment have been refined over time, a portion of girls with higher cognitive and language abilities are at risk of not being identified until later in life (18,(20)(21)(22). A population-based study in the UK showed that females with similar levels of symptom expression to males were less likely to receive a diagnosis of ASD from clinical services (23). Moreover, boys are usually detected by ASD screeners at higher rates than girls, although sex differences in screening scores are not as pronounced (24,25).…”

“…Most males are fascinated by toys on wheels or screen time (e.g., video games), while girls mostly show obsessions with random objects (e.g., stickers, stones, pens, animals) and play obsessive and repetitive games with other toys (16,38). Differences in core ASD symptoms may become more pronounced as individuals age and cultural influences play a larger role into gender differences (23) leading to inconsistent and conflicting results. In addition, the difference in core symptoms could be also related to the change in intervention strategies that occur between toddlerhood to preschool-school age period partly due to transition from "early home based" intervention to "school-based" (23).…”

“…Differences in core ASD symptoms may become more pronounced as individuals age and cultural influences play a larger role into gender differences (23) leading to inconsistent and conflicting results. In addition, the difference in core symptoms could be also related to the change in intervention strategies that occur between toddlerhood to preschool-school age period partly due to transition from "early home based" intervention to "school-based" (23). Also camouflaging is often discussed in relation to sex difference and offers a partial explanation of increased rates of missed or delayed diagnosis.…”

Behavioral gender differences across Pre-School Children with Autism Spectrum Disorders: a cross-sectional study

“…Conversely, other studies found worse social skills in girls (Hartley and Sikora, 2009;Lawson et al, 2018). Moreover, while a recent study by Ros-Demarize et al (2020) reported that females demonstrated greater deficits in social communication, with similar results in both parental reports and standardized observations, a previous study by Mandy et al (Mandy et al, 2012) showed differences in how parents and teachers, who are often the first to recognize potential autistic traits, evaluate social skills. In the latter research, while parents reported an equivalent impairment in social and communication areas in both sexes/genders, teachers more often recognized social difficulties in males since they showed more externalizing problems than females.…”

Sex-Related Changes in the Clinical, Genetic, Electrophysiological, Connectivity, and Molecular Presentations of ASD: A Comparison between Human and Animal Models of ASD with Reference to Our Data

“…In the last few years, sex-related alterations in the clinical presentation of autism spectrum disorder (ASD) among preschool-age children have been described by many investigators [ 3 , 4 ]. However, some studies did not find sex-related differences [ 5 ] or observed behavioral alterations between boys and girls with ASD that were different from those generally described [ 6 ]. The sex differences in the clinical presentations of ASD also point to the possible need to use different tools in the diagnosis of ASD for boys and girls, or at least different diagnostic scores when using the same tools for boys and girls [ 7 ].…”