Are Restrictive and Repetitive Behaviors Associated with Emotion Dysregulation in Youth with Autism Spectrum Disorder?

Background: Although autism spectrum disorder (ASD) is characterized by impairments in social communication and restrictive/repetitive behaviors (RRBs), the extent and severity of RRBs ranges widely among youth with ASD, leading some researchers to question whether RRBs are inherently a core symptom of ASD stemming from a common underlying cause, or a concurrent feature for some but not all individuals. There is a well-documented correlation between the severity of core ASD symptoms and the presence of mental health disorder symptoms, although the nature of this linkage remains poorly understood, specifically whether they are unique and stronger for RRBs as compared to social-communication symptoms. One emerging hypothesis suggests that RRBs may reflect a specific manifestation of underlying emotion dysregulation and therefore measures of RRBs may have strong statistical affinity for measures of emotion dysregulation. A corollary hypothesis is that the RRB cluster is more strongly associated with emotion dysregulation constructs than is the ASD social-communication symptom cluster. A secondary corollary suggests that, of the two main symptom domains of emotion dysregulation, internalizing symptomatology (versus externalizing symptomatology) may be particularly strongly linked with RRBs due to various shared behavior features. Extant research has not yet addressed these hypotheses comprehensively.

Objectives: To explore the relationship between RRBs and emotion dysregulation in youth with ASD.

Methods: Data from the National Database for Autism Research (NDAR) were compiled to examine the patterns of association between well-established continuous symptom measures, namely the Child Behavior Checklist (CBCL; Achenbach & Edelbrock, 1991) and the Social Responsiveness Scale (SRS; Constantino & Gruber, 2012). Participants included all youth with ASD ages 6-18 years old (N=2921) with valid scores for both measures. Linear mixed models (LMMs) were used to test the above hypotheses, accounting for assessments conducted at multiple timepoints. The SRS RRB subscale and Social Communication and Interaction (SCI) subscale were used in the models simultaneously to predict CBCL Internalizing scores. Similarly, the Internalizing and Externalizing CBCL subscales were used simultaneously to predict SRS scores.

Results: In the primary LMM, RRBs were a better predictor of internalizing symptoms (b=.265) than was social-communication symptoms (b=.197). In the secondary LMM, internalizing symptoms were a better predictor of RRB severity (b=1.328) than were externalizing symptoms (b=.443).

Conclusions: This study highlights a substantial and specific relationship between RRBs and emotion dysregulation in youth with ASD. Although by no means resolving diagnostic questions about the centrality of RRBs in the ASD taxon, these results illustrate a specific affinity between RRBs and internalizing symptomatology, as predicted by emerging conceptual models, which aligns with research on the frequent mental health comorbidities seen in ASD as well as theories of “multiple autisms”. Perhaps RRBs are, to some extent, manifestations of underlying emotion dysregulation that also leads to anxiety, depression, aggression, and similar comorbid mental health symptoms and diagnoses. Future research may be able to test RRBs as underlying manifestations of emotion dysregulation more directly with multi-method assessment of internalizing behavior at both neural and behavioral levels in heterogeneous groups of youth with ASD.