Sensory Subtypes of Toddlers With Autism Spectrum Disorder

PURPOSE: Previous studies investigating subtypes or phenotypes of children with autism spectrum disorder (ASD) have done so using behavioral, genetic, and medical characteristics (Ousley & Cermak, 2014). In these studies, cognitive and language factors have consistently been the primary mediators of clustering. Additional research has also attempted to define the contributions of repetitive and sensory-related interests and behaviors (restricted and repetitive behaviors, or RRBs) to cluster individuals with ASD (Bishop et al., 2013; Lord, Bishop, & Anderson, 2015). The Diagnostic and Statistical Manual of Mental Disorders, fifth edition (American Psychiatric Association, 2013), describes any unusual sensory response to the environment, sensory reactivity, or unusual sensory interests as a diagnostic feature for the RRB criterion.

Sensory processing differences have been widely reported in the literature describing children with ASD, and research suggests that these sensory processing differences can help identify clinically meaningful subtypes, or distinct profiles, of children with ASD (Ausderau et al., 2014; Lane, Malloy, & Bishop, 2014). These sensory subtyping studies have used preschool-age and older children and focused subtyping efforts solely on sensory features. Research is needed to both validate and expand on previous studies on sensory subtypes. Therefore, recognizing the relationships between these variables, we investigated subtypes of toddlers with ASD using developmental, diagnostic, demographic, and sensory pattern characteristics. Our research questions were: (1) How many subtypes exist in a sample of toddlers with ASD under age 3 yr? (2) To what extent do these subtypes differ on developmental, sensory, and demographic characteristics?

DESIGN: Retrospective analysis was used for this study. Data resulting from the diagnostic evaluation process of toddlers with ASD were gathered for analysis.

METHOD: Participants included 75 toddlers (54 boys, 21 girls) diagnosed with ASD following a comprehensive interdisciplinary evaluation at a university-affiliated tertiary diagnostic center. The average age of the participants was 28.09 mo (SD = 4.65 mo). Demographic (gender, age), developmental standard scores (cognitive, language, social, motor, adaptive), and sensory pattern (Toddler Sensory Profile; Dunn, 2014) variables were gathered retrospectively for analysis. A latent profile analysis was run to develop a model of groups of participants who clustered on these variables.

RESULTS: The three-profile solution was supported (Bayesian information criterion = 5317.96; entropy = .863). Toddlers in Profiles 1 (n = 30) and 3 (n = 8) showed similar sensation avoiding, sensitivity, and registration patterns, though those in Profile 3 showed less sensory seeking. Sensory symptom severity defined children in Profiles 2 (n = 37), with greater sensation avoiding, sensitivity, and registration difficulties reported when compared to the toddlers in the other profiles. Toddlers in Profile 3 showed higher motor, adaptive, and social scores. Cognitive scores were variable between profiles, with Profile 3 having the highest and Profile 2 the lowest. No significant differences were noted between the profiles for age or communication skill.

CONCLUSION: Distinct subtypes in the current study were defined by sensory processing and developmental performance. These findings have relevance to the variable presentation of individuals with ASD and allow for interpretation of phenotypes that include sensory patterns as well as toddler characteristics. These phenotypes likely have implications for assessment and intervention aimed at increasing toddlers’ active engagement required for participation in occupations. Additionally, findings may have implications for research studies investigating the etiology of ASD and the variable responding of individuals to intervention programs.

References

American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.

Ausderau, K. K., Furlong, M., Sideris, J., Bulluck, J., Little, L. M., Watson, L. R., . . . Baranek, G. T. (2014). Sensory subtypes in children with autism spectrum disorder: Latent profile transition analysis using a national survey of sensory features. Journal of Child Psychology and Psychiatry, 55, 935–944. https://doi.org/10.1111/jcpp.12219

Bishop, S. L., Hus, V., Duncan, A., Huerta, M., Gotham, K., Pickles, A., . . . Lord, C. (2013). Subcategories of restricted and repetitive behaviors in children with autism spectrum disorders. Journal of Autism and Developmental Disorders, 43, 1287–1297. https://doi.org/10.1007/s10803-012-1671-0

Dunn, W. (2014). Sensory Profile 2 manual. San Antonio, TX: Pearson.

Lane, A. E., Malloy, C. A., & Bishop, S. L. (2014). Classification of children with autism spectrum disorder by sensory subtype: A case for sensory-based phenotypes. Journal of Autism Research, 7, 322–333. https://doi.org/10.1002/aur.1368

Lord, C., Bishop, S., & Anderson, D. (2015). Developmental trajectories as autism phenotypes. American Journal of Medical Genetics, Part C: Seminars in Medical Genetics, 169, 198–208. https://doi.org/10.1002/ajmg.c.31440

Ousley, O., & Cermak, T. (2014). Autism spectrum disorder: Defining dimensions and subgroups. Current Developmental Disorders Reports, 1, 20–28. https://doi.org/10.1007/s40474-013-0003-1