Exploring the Relationship Between Sensory and Social Symptoms of Autism

Background: Children with autism spectrum conditions (ASC) often show atypical sensory reactivity symptoms in addition to social difficulties compared to typically developing (TD) children. It is unknown, however, whether sensory and social symptoms in ASC might be related to one another. To test this relationship we compared children with ASC to children who exhibit similar sensory symptomatology but do not have ASC, that is, children with the suggested diagnostic term ‘sensory processing disorder’ (SPD).

Objectives:  The goals of this study were to determine if a) sensory and social symptoms are related, and b) if children with ASC could be distinguished from children with SPD based on sensory and/or social features. Specifically, we sought to differentiate children with ASC and SPD on sensory subtypes (e.g. over-reactive, under-reactive and sensory craving) and amount of sensory symptoms and/or on social features, specifically empathy using parent questionnaires.

Methods: The study included 210 participants: 68 children with ASC, 79 children with SPD and 63 typically developing (TD) children. We used the Sensory Processing Scale Inventory to measure sensory symptoms (over-reactivity, under-reactivity and sensory craving); the Autism Spectrum Quotient (AQ) to measure autistic traits, and the Empathy Quotient (EQ) to measure social skills.

Results: Children with ASC and SPD showed more sensory symptomatology than TD children (p< .01). Furthermore, even though children with SPD had higher empathy scores compared to children with ASC, they had lower empathy scores compared to TD children (p< .01). Last, sensory symptomatology and social features showed a negative correlation with each other, across groups.

Conclusions: Taken together, our findings suggest that there is a relationship between sensory symptomatology and social aspects of ASC. Children with ASC are most affected by sensory symptoms, and show lowest empathy. Children with SPD lie in between children with ASC and typical developing children on these measures. Future longitudinal studies are needed to explore if children with ASC and SPD both start with the same amount or type of sensory symptoms in early childhood and whether there is a difference in the type of sensory symptoms they display. This study also sheds light on the similarities and differences between children with ASC and SPD. Improved sensory and social phenotyping is an essential first step towards reducing diagnostic confusion between ASC and SPD.