Associations Between Sensory Response Patterns and Symptoms of ADHD in Children with ASD

Background:  Although the DSM-5 allows for dual diagnosis of ASD and ADHD, debate continues regarding the validity of comorbidity with estimates spanning 14-78% (Gargaro, et al., 2011). This sizable comorbidity range may suggest that symptoms of inattention and hyperactivity associated with ADHD are not consistently defined across studies or worse, suggest misinterpreted symptoms.

ADHD is the second most common co-occurring diagnosis with ASD (Simonoff et al., 2008) and if co-occurring diagnoses can be addressed early in development then overall outcomes in children with ASD may be improved. Although ADHD is most frequently addressed with stimulant medications in children who are otherwise typically developing, stimulant medications can result in negative side effects in some children with ASD. Thus, distinguishing attention symptoms that are intrinsic to ADHD versus attention symptoms that are features of ASD may be an important objective for early and appropriate diagnosis and intervention.  We were interested in understanding the extent to which parent reported symptoms of ADHD are associated with unusual sensory processing.   

Objectives: (1) To examine associations between symptoms of ADHD (Inattention and hyperactivity/impulsivity) and sensory response patterns (hyporesponsiveness, hyperresponsiveness, and sensory seeking) and (2) To examine associations between symptoms of ADHD and sensory responses to social and nonsocial sensory stimuli in children with ASD. 

Methods:  15 preschool children with ASD (CA: M=58 months, SD=11; MA: M=36 months, SD=13) were assessed for symptoms of attention through the ADHD Rating Scale IV-Home Version, an 18-item parent questionnaire based on the DSM-IV criteria for ADHD diagnosis (DuPaul et al., 1998) that has been successfully used to assess symptoms of ADHD in preschool children (McGoey et al., 2007). The Sensory Experiences Questionnaire, version 2.1 (SEQ 2.1; Baranek, 1999), a 42-item caregiver questionnaire was used to assess sensory responsiveness (hyporesponsiveness, hyperresponsiveness, sensory seeking) across modalities (e.g., visual, tactile, auditory). 

Results: (1) Inattention was significantly associated with sensory hyperresponsiveness, r(15) = .64, p = .01, association with sensory hyporesponsiveness was nearly significant, r(15) = .51, p = .06.  Inattention was not significantly associated with sensory seeking, r(15) = .21, p = .46. Hyperactivity/Impulsivity was significantly associated with sensory hyporesponsiveness, r(15) = .58, p = .25 and sensory hyperresponsiveness, r(15) = .55, p = .022, but not with sensory seeking, p = .87.  (2) Inattention and Hyperactivity/Impulsivity were both associated with responsiveness to social stimuli, r(15) = .71, p = .003 and r(15) = .65, p = .01 but only Inattention was associated with nonsocial stimuli r(15) = .54, p = .04.

Conclusions: The findings of this study may suggest that parents could have difficulty distinguishing between attention symptoms characteristic of ASD versus ADHD.  Alternatively, sensory response patterns may influence the development of attention. Additionally, both subcomponents of ADHD are significantly associated with social attention while only inattention was associated with nonsocial stimuli. Further research is needed to better understand the nature of the associations between symptoms of ADHD and sensory response patterns in ASD.