Psychological Clinic, #203B
July 17, 2013, 02:30 PM to 04:00 PM
This dissertation examines the development of repetitive and restricted behaviors and interests (RRBIs) in children and adolescents with Autism Spectrum Disorder (ASD). We examined RRBI ratings across the gold-standard diagnostic measures of the ADOS, a clinician observation, and the ADI-r, a parent developmental history report. The purpose was to examine whether there are distinct factors of RRBIs and whether these factors show differences across age and functioning level. Exploratory and confirmatory factor analyses for the ADOS and ADI-r resulted in a two-factor model of “Cognitive-Restrictive” behaviors and “Motor-Sensory” behaviors. The total RRBI scale, the Cognitive-Restrictive subscale, and the Motor-Sensory subscale all showed similar decreases in behavior scores across age groups. Significant rating decreases did not occur, however, until middle childhood to adolescence, indicating that improvements for RRBIs may not occur until children reach an older developmental stage. Further, while total RRBI scores demonstrated an association with IQ, factor scores revealed only the Cognitive-Restrictive scale was associated with IQ. Individuals with low IQs demonstrated higher ratings and less improvement for Cognitive-Restrictive scores. We also found that RRBI items on the ADOS and ADI-r correlate relatively poorly across the measures. Implications for practice include tailoring interventions to the differences of Cognitive-Restrictive and Motor-Sensory behaviors and specifically targeting Cognitive-Restrictive RRBIs for individuals with lower IQs.