Non-verbal IQ and change in restricted and repetitive behavior throughout childhood in autism: a longitudinal study using the Autism Diagnostic Interview-Revised

Abstract

Background Restricted and repetitive behavior (RRB) is one of the characteristic features of Autism Spectrum Disorder. This domain of symptoms includes a broad range of behaviors. There is a need to study each behavior individually to better understand the role of each in the development of autistic children. Moreover, there are currently no longitudinal studies investigating change in these behaviors over development. Methods The goal of the present study was to explore the association between age and non-verbal IQ (NVIQ) on 15 RRB symptoms included in the Autism Diagnostic Interview-Revised (ADI-R) over time. A total of 205 children with ASD were assessed using the ADI-R at time of diagnosis, at age 6 years, and at age 11 years, and with the Wechsler Intelligence Scales for Children—Fourth Edition (WISC-IV) at age 8 years. Results The proportion of children showing each RRB tended to diminish with increasing age, except for sensitivity to noise and circumscribed interests, where the proportion increased over time. Although there was no significant main effect of NVIQ, there was a significant interaction between age and NVIQ. This was mainly driven by Difficulties with change in routine, for which higher NVIQ was associated with the behavior remaining relatively stable with age, while lower NVIQ was associated with the behavior becoming more prevalent with age. Limitations The study focused on the presence/absence of each RRB but did not account for potential changes in frequency or severity of the behaviors over development. Furthermore, some limitations are inherent to the measures used. The ADI-R relies on parent report and hence has some level of subjectivity, while the Wechsler intelligence scales can underestimate the intellectual abilities of some autistic children. Conclusions These results confirm that specific RRB are differentially linked to age and NVIQ. Studying RRB individually is a promising approach to better understanding how RRB change over the development of autistic children and are linked to other developmental domains.

Characterizing individual differences in children and adolescents with autism spectrum disorder: a descriptive study

“…Regarding RRB, recent studies showed that more RRB was present in adolescent boys than in younger groups of male children with ASD ( Van Wijngaarden-Cremers et al, 2014 ; Stroth et al, 2022 ). However, the current findings supported a recent longitudinal study showing a reduction in RRB with increasing age ( Courchesne et al, 2021 ). Specifically, using the ADI-R, Courchesne et al (2021) studied a population of 206 children at aged 6 and 8 years, respectively.…”

A machine learning-based diagnostic model for children with autism spectrum disorders complicated with intellectual disability

“…Therefore, the diagnostic model constructed in this study is only suitable for children diagnosed with autism. For a long time, the relationship between RRBs and IQ has not reached a consensus ( 57 , 58 ). The diagnostic model constructed by ML in this study suggests that the higher the score of repetitive, stereotyped behavior in children with autism, the greater the possibility of combined ID.…”

Development of Restricted and Repetitive Behaviors from 2-19 and Internalizing Symptom Outcomes in a Longitudinal Study of Autism

“…In contrast to some prior work (Baribeau et al, 2021a; Gotham et al, 2013, 2014; Lidstone et al, 2014; Rodgers et al, 2012; Stratis & Lecavalier, 2013) we found little evidence for associations between RRBs and internalizing symptoms in autistic adults. By longitudinally characterizing change and stability in RRB subtypes from ages 2-19, this paper adds to previous work in this sample (Richler et al, 2010) as well as work conducted in other samples ((Bishop et al, 2013; Courchesne et al, 2021; McDermott et al, 2020; Uljarević et al, 2021) that have found differing profiles of RRB symptoms in autistic individuals both within and across age groups. This study also corroborates findings from other longitudinal samples that, on average, core ASD symptomology decreases with increasing age (Seltzer et al, 2004; Taylor & Seltzer, 2010).…”

“…Though few studies have examined RRBs longitudinally from early childhood to early adulthood, prior work in separate samples has examined changes in RRBs across childhood. Similar to Richler et al, (2010), these studies have found that many RRB behaviors increase from early to mid-childhood (Courchesne et al, 2021;Guthrie et al, 2013;Moore & Goodson, 2003). In contrast, cross-sectional studies of adults with ASD indicate RSM behaviors decrease with increasing age (Bishop et al, 2013;Esbensen et al, 2009;Evans et al, 2017;Uljarević et al, 2021).…”