Speech Development Across Subgroups of Autistic Children: A Longitudinal Study

Area of Science:

• Developmental Psychology
• Speech-Language Pathology
• Autism Spectrum Disorder Research

Background:

• Previous research identified distinct speech profiles in autistic children.
• Limited understanding exists regarding the long-term speech development trajectories and subgroup stability in this population.

Purpose of the Study:

• To describe speech development trajectories and subgroup stability over 12 months in young autistic children.
• To identify potential predictors of speech outcomes within 12 months.

Main Methods:

• Longitudinal study of 22 autistic children (aged 2;0-6;11 years) over 12 months.
• Utilized independent and relational speech analyses, vocabulary size, and nonverbal communication for clustering.
• Assessed speech trajectories and subgroup stability.

Main Results:

• Observed varied speech development trajectories, especially in children with 'low language and low speech' at baseline.
• Receptive vocabulary and consonant inventory at baseline may predict speech outcomes at 12 months.
• Identified a stable subgroup (n=3) with low expressive vocabulary/speech but higher receptive vocabulary and gesture use.

Conclusions:

• Speech development in autistic children is heterogeneous, with distinct trajectories and varying subgroup stability.
• Early receptive vocabulary and phonological skills show potential as predictors of later speech development.
• A specific profile of low expressive language with preserved receptive language and gestural communication may be a stable characteristic in some autistic children.