Examining the Relation Between Sensory Sensitivity and Obsessive-Compulsive Behaviors in Autism Spectrum Disorders As Moderated by Early Language Acquisition

Background: Research indicates a link between autism spectrum disorders (ASDs) and obsessive-compulsive behaviors (OCB).  Moreover, sensory sensitivity (SS) has been established as a common characteristic in individuals with ASD and potentially in individuals with elevated OCBs.  However, there is limited research exploring the relation of SS to OCB in high-functioning individuals with ASD, which is surprising given that both SS and OCB have high prevalence in individuals affected with ASD. A key diagnostic distinction within ASDs is meeting the developmental milestones of language acquisition. Given that a delay in the development of language has shown to be related to impairment in related mechanisms, such as social cognition, it is posited that obsessions and subsequent compulsions would be more pronounced in individuals without a language delay. For this reason, we examined the moderating effect of language acquisition in the relation between SS and OCBs in individuals with high-functioning ASD. 

Objectives: 1) To explain the relation between SS and OCBs in high-functioning individuals with ASD. 2) To examine the moderating effect of language acquisition in the relation between SS and OCBs. 

Methods: Individuals with high functioning autism (HFA), Asperger’s syndrome (AS), and Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS) (n=129; mean FSIQ=98.46; mean age=13.66; 91.4% male) were assessed in the following domains: Full Scale Intelligence Quotient (FSIQ) as measured by the WISC or WAIS, obsessive-compulsive behaviors as measured by the symptom checklist and ordinal scales of the Yale-Brown Obsessive-Compulsive Scale (TS-OCD), early language acquisition as measured by the ADI-R, and sensory sensitivity as measured by selected items on the ADI-R, ADOS, and TS-OCD interview.   

Results: Hierarchical multiple linear regression was used to test the relation between SS and OCBs, controlling for age and FSIQ. Parallel models with obsessions and compulsions as the outcome variables were also tested. Language acquisition was included in models as a moderator of the relation between SS and OCBs. SS and language acquisition each accounted for unique variance in OCBs, F(4, 125) = 5.02, p<.01, as did their interaction, F(5, 124) = 4.91, p<.001. When looked at separately, language acquisition moderated the relationship between SS and compulsions, F(5, 124) = 3.02, p<.05, but not SS and obsessions.  The relation between SS and OCBs was significant for individuals with HFA with late language acquisition, but there was no association for those with early language acquisition.

Conclusions: Results suggest that higher levels of SS predict increased rates of OCBs in high-functioning individuals with ASD, and that the magnitude of this relationship is influenced by the presence of early language acquisition. This study provides evidence for further exploration of the role SS and early language acquisition have on the manifestation of ASD related symptom presentation.