Restrictive and Repetitive Behaviors in Young Children with Autism:

Background:  Restricted and repetitive behaviors (RRB) comprise one of two core symptom domains in DSM-5 Autism Spectrum Disorder (ASD;  American Psychiatric Association, 2013).  RRBs reportedly decrease with age across the life span (e.g., Esbensen et al., 2009) but may develop or remain constant in young children with ASD (Harrop et al., 2014). Further, parents report their child’s RRB differently than clinicians (Lemler, 2012).  Additional research is necessary to characterize the nature of the relationship between age and RRBs in young children with ASD and by informant. 

Objectives:  To investigate (1) the relationship between RRBs and age in young children with ASD, and (2) correlations between parent and clinician ratings of RRBs.

Methods:  Preliminary data are drawn from a comprehensive baseline assessment of an ongoing R01 study conducted in a community clinic parent training therapy program.  Parents completed the Repetitive Behavior Scale- Revised (RBS-R; Lam & Aman, 2007) with six dimensions: stereotyped, self-injurious, compulsive behaviors, ritualistic, sameness and restricted interests plus a total score and demographic forms.  The Autism Diagnostic Observation Schedule, 2^nd edition (ADOS-2; Lord et al., 2012) and Ohio Autism Clinical Impression Scale (OACIS; Butter & Mulick 2006) were administrated by trained, research reliable project staff.  This sample includes 45 children (80% male) ages 2-10 (M = 4.7 years; SD = 2.4), 31% Hispanic, 20% autistic disorder, 2% Asperger’s, 16% pervasive developmental disorder, and 56% autism spectrum disorder (all cases validated by positive ADOS-2) and their primary caregivers. Regression analyses were conducted to examine child age associated with each outcome variable.  Age groups were constructed: 2 yrs, 3-4 yrs and 5+ yrs; to compare RRBs by age and informant.  Pearson correlation coefficients were used to examine relationships between the three measures for each age group.

Results:  There was a significant positive relationship between age and both clinician rated scales and parent rated scale, total score on RBS-R, such that as age increases, scores on the RRB measures also increase (see Tables 1 & 2 for all results reported in this section).  There was no correlation between any of the RBS-R subscales or total score with clinician rated measures for the overall sample indicating poor agreement of RRBs between parent and therapist.  When comparing age categories, a few RBS-R subscales became correlated with clinician ratings.  However, these results should be considered exploratory at this point due to the small n per group.

Conclusions:  Findings suggest that age is associated with an increase in RRBs for young children with ASD.  Overall, there were few reports of RRBs in toddlers compared to preschoolers and children. Additionally, there was poor agreement on RRBs between parent and trained clinical observer. This suggests that age and RRB likely have a unique relationship in early development, perhaps because RRBs are still emerging and may not be as apparent in the youngest age groups.  The finding that parent report of RRBs does not correlate with clinician report of RRB also suggests that further research is needed to determine potential factors influencing this disparity.