Examining the Time Course of Repetitive and Restricted Behaviors of Children with ASD throughout Childhood and Adolescence. Taxonomy for Parents and Providers

Background:  Restricted and repetitive behaviors (RRBs) include a broad category of behaviors which are considered core characteristics required for a diagnosis of Autism Spectrum Disorder (ASD) according to the Diagnostic and Statistical Manual (DSM-V; American Psychiatric Association, 2013). Parents of children with ASD have often reported that RRBs can be the most stressful aspect of raising their child (Bishop, Richler, Cain & Lord, 2007). Earlier research on RRBs may be difficult to generalize, since those studies tended to focus on a limited number of RRBs, measured predominantly by tools designed for assessing ASD and not RRBs per se. While previous studies have subdivided RRBs into Repetitive and Sensory Motor behaviors (RSM) and Insistence on Sameness behaviors (IS), no study has provided a comprehensive taxonomy of the most commonly presenting RRBs by age group. 

Objectives:  This study uses a newly standardized measure, the Behavior and Sensory Interest Questionnaire (BSIQ) (Hanson et. al. 2015) to classify a wide range of RRBs. Furthermore, by aggregating data by age from a large sample size, a proposed timeline of RRBs emergence has been created. 

Methods:  A sample of 503 children with ASD (82% male) was drawn from the Simons Simplex Collection and the Boston Autism Consortium. Participant ages were between 24-216 months, (mean=92.3, SD=45.75). ASD diagnosis was verified with the Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview-Revised (ADI-R). Parents were administered the BSIQ, designed to evaluate the number, type, and intensity of RRBs, by a trained clinician. Preliminary analysis of behavior frequency determined top presenting RRBs in seven different groups. Groups were determined by age of participant.

Results:  Preliminary analysis reveals three primary patterns of prevalence of RRBs in children with ASD. Repetitive motor behaviors often remain consistent in their prevalence across ages, for example, more than 33% of children with ASD present with flapping throughout their development. Sensory seeking behaviors generally showed decline with age, such as seeking deep pressure, which presented between 48-55% for children under the age of nine, but drops as low as 30% for children above the age of nine. In contrast, Insistence on Sameness behaviors are not as prevalent (26-36%) in 2-7 year olds, and instead increase with age, up to 44% in children 9-12 years of age.

Conclusions:  Research has shown the impact of RRBs on adaptive functioning, so it is important to document the prevalence across childhood development. Further analysis will reveal the significance of RRB patterns of emergence and frequency. This information will produce a comprehensive taxonomy that is useful for families, clinicians, and researchers in the diagnosis and treatment of children with ASD.