Relations Among Repetitive Behaviors and Language in Toddlers at Familial Risk for Autism

Background:

Previous studies have shown that restricted and repetitive behaviors (RRBs) are negatively associated with communication ability among school-aged children and adolescents with ASD (e.g., Dominick et al, 2017). However, the relationship between RRBs and communication during early childhood has not been well-characterized, and existing findings are mixed. Most previous work has examined communication as a single construct rather than decomposing communication into components of expressive, receptive, and social communication. Understanding whether RRB differentially relates to expressive, receptive, and social communication could shed light on previous disparate findings and inform intervention.

Objectives:

The purpose of this study was to examine relations among receptive and expressive language, socialization, and RRBs for 24-month-olds at high familial risk of ASD. A secondary purpose was to evaluate whether relations differ between children who did versus did not meet diagnostic criteria for ASD.

Methods:

Participants included n=426 toddlers at high familial risk for ASD. Of these, n=113 met criteria for ASD classification at age 24 months (HR-ASD) and n=313 did not (HR-Neg). We measured using the Restricted Behavior Scale-Revised (RBS-R, Bodfish et al. 2000), and represented RRB using a three-factor model with lower-order RRB, higher-order RRB, and SIB factors (Mirenda et al., 2010). We measured receptive and expressive language using the relevant subscales from the Mullen Scales of Early Learning, Macarthur-Bates Communication Development Inventory, and the Vineland Adaptive Behavior Scales (MSEL; Mullen, 1995; MCDI, Fenson et al., 1993; and VABS-II; Sparrow, Balla, & Cicchetti, 2005), and we measured socialization with the VABS-II. We used structural equation modeling to compare the extent to which data fit five models testing different relations among receptive and expressive language, socialization, lower-order RRB, higher-order RRB, and self-injurious behavior (SIB). Models controlled for sex and diagnostic status. The measurement model was confirmed using confirmatory factor analysis prior to running the full model, and all factors showed acceptable fit. We next compared model fit for groups on the basis of ASD classification (HR-ASD vs. HR-Neg).

Results:

The best-fitting model included receptive and expressive language predicting lower-order RRB, higher-order RRB, and SIB. This model had acceptable global fit with significant direct paths from receptive language to all RRB factors. No direct paths from expressive language to RRB were statistically significant. Global model fit was also acceptable for the separate groups of HR-ASD and HR-Neg. Factor loadings and covariances were similar between groups. When considering subgroups, the only significant direct path was from receptive language to lower-order RRB among the ASD group.

Conclusions:

These findings inform an understanding of early relations of RRB to communication by showing evidence of an association between receptive language and RRB for toddlers at high risk for ASD. Additionally, these findings suggest that associations among language and RRB differ minimally between children at high familial risk with and without an ASD classification.