Anxiety, Arousal, and Sensory Processing In Children with ASD

Background:  Neither anxiety or sensory processing are used in diagnostic characterization of ASD, although both are highly prevalent^1,2,3,4. While far from established, deficits in the ability to modulate incoming sensation have been linked with anxiety⁵. Sensory over-responsivity (SOR) to environmental stimuli has been documented in children with ASD^6,7, and there is an indication that SOR and anxiety may be linked in both children and adults with ASD^1,7. Finally, ASD response to sensory challenge has been characterized by altered arousal⁴. Further examination of the link between anxiety, disordered sensory processing, and electrodermal activity (EDA) in children with ASD was the basis for this study.

Objectives:  Further examine the anxiety, SOR, and arousal relationship in children with ASD.

Methods:  

• Participants- Children ages 6-12 (ASD=27; TYP=28), no other impairments; IQ> 70
• Design- Cross sectional repeated measures to assess electrodermal response (EDR) and cortisol response to sensory challenge; between group differences were examined for behavioral measures
• Measures- Short sensory profile (SSP); Reynolds Child Manifest Anxiety Scale (RCMAS) (total and subscales); Child Behavioral Checklist (CBCL) DSM Anxiety Scale, baseline EDA and non-specific responses.

Results:  Children with ASD showed significantly greater total anxiety and more frequent clinically significant total anxiety than TYP. Further, ASD and TYP groups differed significantly on RCMAS subscales of worry/over-responsiveness and social concern and concentration. Children with ASD had significantly higher baseline EDA and non-specific responses than TYP children, indicating higher baseline arousal. Children with ASD also demonstrated SOR across tactile, movement, visual/auditory, and taste/smell domains of the SSP, along with sensory seeking. Tactile and visual/auditory sensitivity significantly correlated with CBCL DSM anxiety.

Conclusions:  

Elevated anxiety is documented in ASD¹. High arousal levels identified here further  supports the high anxiety.  SOR has been recognized by other investigators ^4,8,9,. Here, we linked SOR to both anxiety and EDR patterns suggestive of elevated arousal. While such a link has been questioned by some³, others ⁷ have suggested that some children with ASD have faulty arousal mediation systems, interfering with optimal environmental interaction. Increased arousal, sensory sensitivities, and anxiety can interfere with participation in many daily activities. Further investigation of the link between anxiety, arousal and participation in ASD is warranted. Better understanding the features of ASD, their inter-relationship and impact on participation in daily activities, will allow definition of the issues and improve our ability to provide intervention.

References:
1. Green, SA & Ben-Sasson, A. JADD. DOI 10.1007/s10803-010-1007, 2010.
2. Reynolds, S., & Lane, S. J. AJOT, 63, 433-440, 2009
3. Rogers, SJ & Oznoff, S. J Child Psychol Psychiatry 46, 1255-1268, 2005
4. Schoen, SA, et al. Res Aut Spect Dis (2), 417-429, 2008
5. Ayres, A. J. Sensory Integration and Learning Disorders. Los Angeles: Western Psychological Services, 1972.
6. Baranek GT,, et al. J Child Psychol Psychiatry. 47:591-601, 2006.
7. Pfeiffer, E. UMI Microfilm. (UMI No. 3099904), 2003.
8. Ben-Sasson, et al. J Child Psychol Psychiatry 49 , 817-825, 2008
9. Liss, M., et al. (2006)  Autism, 10, 155-172.