Sensory Responses in Optimal Outcome Children with a History of Autism Spectrum Disorders

Background: A study is currently following children who have a history of autism spectrum disorder (ASD), but who no longer meet diagnostic criteria for the disorder. These children have achieved social and language skills within the average range for their ages and receive little or no school support. Several recent studies suggest that this small subset of children, once diagnosed with ASD, achieve an "optimal outcome" (Sutera et al., 2007, Kelley et al., 2006, and Helt et al., 2008).

Objectives: While not included in the ASD diagnostic criteria, abnormal responses to sensory stimuli are frequently noted in children with ASD.  This study examines parent report of sensory responses in a group of children who have achieved optimal outcome (OO) as compared to children with high-functioning autism (HFA). 

Methods: The Autism Diagnostic Interview-Revised (ADI-R) was completed by the parent of 18 HFA children (mean age = 13.06, mean IQ = 110.35) and 29 OO children (mean age = 12.93, mean IQ = 114.04).  Item scores on the ADI-R range from 0 to 3, with a higher score indicating more severe and frequent behaviors.  Three items on the ADI-R relate to sensory functioning: “Unusual Sensory Interests,” “Undue General Sensitivity to Noise,” and “Abnormal, Idiosyncratic, Negative Response to Specific Sensory Stimuli.”  The two groups were compared on both past and present parent report for each of the items, as well as on a past and present average of the three items. 

Results: There were no significant differences between the HFA and OO children, currently or in the past, for “Unusual Sensory Interests” (Current: M(OO)=0.31, M(HFA)=0.56; Ever: M(OO)=0.86, M(HFA)=0.89) or “Undue General Sensitivity to Noise (Current: M(OO)=0.48, M(HFA)=0.72; Ever: M(OO)=1.14, M(HFA)=1.67).”  There was a marginally significant difference between the HFA and OO children currently on “Abnormal, Idiosyncratic, Negative Response to Specific Sensory Stimuli,” with the HFA children scoring higher than the OO children, M(OO)=0.21, M(HFA)=0.67, p=.056.  Additionally, on the past rating of this item, HFA children had significantly more abnormal responses to sensory stimuli than OO children, M(OO)=0.48, M(HFA)=1.28, p<.05. Forty-four percent of the HFA children received a rating of 2 or 3 on this item, compared to only ten percent of the OO children.  Abnormal responses most commonly resulted from auditory stimuli, such as babies crying, vacuuming, or toilets flushing in the HFA children, and crowds or high-pitched laughing in the OO children. HFA children also exhibited more abnormal sensory responses than OO children, both currently and in the past, when compared on the average of the three sensory items (Current: M(OO)=0.33, M(HFA)=0.65, p<.05; Ever: M(OO)=0.83, M(HFA)=1.28, p<.05).

Conclusions: These preliminary results based on parent report suggest that OO children display significantly fewer abnormal sensory behaviors, both currently and in the past, than HFA children.  HFA children specifically showed significantly greater “Abnormal, Idiosyncratic, Negative Response to Specific Sensory Stimuli” in the past than OO children.  However, OO children still exhibited some abnormal sensory behaviors, particularly in the past.  Further research including larger samples, particularly of HFA children, is needed to support this conclusion.