A path model of expressive vocabulary skills in initially preverbal preschool children with autism spectrum disorder

We examined direct and indirect paths involving receptive vocabulary and diversity of key consonants used in communication (DKCC) to improve understanding of why previously identified value-added predictors are associated with later expressive vocabulary for initially preverbal children with autism spectrum disorder (ASD; n = 87). Intentional communication, DKCC, and parent linguistic responses accounted for unique variance in later expressive vocabulary when controlling for mid-point receptive vocabulary, but responding to joint attention did not. We did not confirm any indirect paths through mid-point receptive vocabulary. DKCC mediated the association between intentional communication and expressive vocabulary. Further research is needed to replicate the findings, test potentially causal relations, and provide a specific sequence of intervention targets for preverbal children with ASD.