Changes in Restricted Repetitive Behaviors with age: A study of high-functioning adults with Autism Spectrum Disorders

The existing literature suggests that while impairments in Autism Spectrum Disorders (ASDs) continue into adulthood, some behavioral symptoms tend to abate with age. However, there is a dearth of research examining changes in ASD symptoms from childhood to adulthood, especially for Restricted Repetitive Behaviors (RRBs). We examined age-related changes in RRBs in a sample of 34 high-functioning adults with ASDs at current age and retrospectively at age 4–5 years using the Autism Diagnostic Interview—Revised, and the Repetitive Behavior Scale—Revised. We found significant changes in all RRBs over time with the exception of the Self-injurious Behavior subscale of the RBS-R. In addition, the degree of change also differed for RRB subtypes. Based on the RBS-R, the highest proportion of participants showed improvements on the Compulsive Behavior subscale (75%), and the lowest proportion showed improvement on the Restricted Behavior subscale (44.1%). We also found a low base rate for certain symptoms (e.g., self-injurious behavior, unusual preoccupations, and unusual sensory interests) in this sample of higher-functioning individuals with ASDs. Future research should examine further changes in RRBs in late adulthood and also evaluate contextual variables that are likely to be related to symptom abatement over time.