The Effects of Early Intervention on the Expressive Language Outcomes of Children with Autism Spectrum Disorder: A Systematic Review

Background: Autism Spectrum Disorder (ASD) is characterized by persistent challenges in social communication as well as restricted and repetitive behaviors and is often observable in early childhood. Expressive language delays are common in young children diagnosed with ASD. Expressive language includes any form of communicative output, such as verbal language, sign language, and the use of alternative and augmentative communication (AAC). Early intervention, for the purpose of this systematic review, is defined as speech and language services provided before a child is 5 years (60 months) of age. Evidence suggests that early intervention can lead to positive outcomes in the symptoms of children with ASD. Objective: To determine whether early intervention of ASD in children between 0-59 months of age has positive effects on expressive language development. Methods: A systematic search of the PsychINFO, PubMED, CINAHL, ERIC, and LLBA database was conducted, followed by a qualitative analysis of relevant articles. Studies included monolingual (i.e., English) children who were diagnosed with ASD. Studies were systematically graded and processed using inter-rater procedures. Results: Fourteen articles were included based upon inclusionary criteria. The overall quality of the studies was moderate. The most widely used early intervention techniques included the Early Start Denver Model (ESDM) and Pivotal Response Training (PRT). Conclusions: Consistent high-interval (i.e., 25 hours per week), behaviorally-based early intervention (i.e., before 40 months) may lead to positive outcomes in expressive language development. Clinicians working with young children with ASD should implement behaviorally-based, empirically-supported interventions, such as ESDM or PRT. Future research should prioritize high-quality study designs (e.g., randomized control trials) with larger sample sizes of children diagnosed with ASD, which is necessary to discern a direct relationship between behaviorally-based early intervention and expressive language outcomes for children with ASD.https://scholarworks.uvm.edu/csdms/1008/thumbnail.jp