Adaptive Behavior Profiles in Toddlers with Autism Spectrum Disorders

Background:  Efforts have been made to lower the age at which ASD is first diagnosed. Additional diagnostic information, such as cognitive and adaptive behavior testing, can supplement results from an autism assessment to help improve clinical decision making. Several studies have explored the differences in adaptive behavior between children with autism spectrum disorder (ASD) and other developmental disabilities. An “autism profile” of adaptive behavior has been identified that ranks Vineland Adaptive Behavior Scale domain scores, from highest to lowest, as motor, daily living, communication, and socialization scales. Perry, Flanagan, Geier, et al. (2009) confirmed this profile in a large sample of children under 6 years, finding that children with ASD scored lower than children with ID on communication and socialization scores. Of interest is whether the same adaptive behavior profile is also found in toddlers aged 12 to 36 months since the introduction of the Vineland – II (VABS-II), the DSM-5 revised diagnostic criteria, and tools allowing for the earlier identification of ASD, such as the ADOS-Toddler Module. 

Objectives:  To identify and compare adaptive behavior profiles of toddlers diagnosed with ASD versus global developmental delay (GDD) based on DSM-5 criteria in a sample of toddlers referred to the developmental assessment center of a pediatric hospital.  

Methods:  A retrospective chart review was conducted to review clinical assessment records of children presenting for a diagnostic evaluation at the developmental disabilities clinic of a large Midwestern pediatric hospital. Children who presented with concerns of ASD or a developmental delay were evaluated using DSM-5 criteria, cognitive assessments, the VABS-II, and the appropriate ADOS module (Toddler, 1, or 2 few to no words) if concerns of ASD were presented. A final sample of toddlers with ASD (n=54) and global developmental delay (n=54) was used.

Results:  VABS-II communication and daily living skills scores were significantly correlated with Mullen Early Learning Composite scores for toddlers with ASD. For the ASD sample administered with ADOS-Toddler module, a moderate negative correlation was found between VABS-II communication, socialization, and daily living skills scores and ADOS scores. VABS-II subdomain scores confirmed a pattern similar to that found by other studies of the “autism profile” in toddlers diagnosed with ASD using DSM-5 criteria. Additionally, toddlers with ASD were found to have comparable scores on the daily living and motor scales to toddlers with global developmental delay. Toddlers with ASD had significantly lower communication and socialization scores than toddlers with global developmental delay. 

Conclusions:  The “autism profile” of adaptive behavior is relevant for toddlers aged 12-36 months, and remains relevant for use with newer assessment tools and systems, specifically the VABS-II, and the DSM-5 criteria for ASD. This profile should be considered to supplement clinical decision making when required to make a differential diagnosis between ASD and another disorder in toddlers. 

References: Perry, A., Flanagan, H. E., Geier, J. D., & Freeman, N. L. (2009). Brief Report: The Vineland Adaptive Behavior Scales in Young Children with Autism Spectrum Disorders at Different Cognitive Levels. Journal of Autism and Developmental Disorders, 39(7), 1066–1078.