Children with autism spectrum disorders who do not develop phrase speech in the preschool years.
One in four autistic preschoolers still have no phrase speech after two years of center therapy, and all of them also have intellectual disability.
01Research in Context
What this study did
A clinic tracked 165 preschoolers with autism for two years. All kids got the same center-based services. The team wanted to know how many would still have no phrase speech after all that help.
They also checked if IQ scores could tip us off about who would stay non-verbal.
What they found
One in four children still had no phrase speech after two full years of therapy. Every single one of those kids also had intellectual disability.
Cognitive level, not therapy hours, was the clearest red flag.
How this fits with other research
D'Agostino et al. (2025) extends this picture. They show that restricted and repetitive behaviors split into three clusters in verbal kids but only two in non-verbal kids. The extra cluster is speech-based, so it simply can’t appear if the child has no words.
Hatton et al. (2004) is a predecessor that followed toddlers diagnosed at age 2. They found diagnosis stayed firm to age 5, and later IQ shifts hinged on starting ability, not on how much therapy families packed in. That older study sets the stage for the 2015 finding that cognitive level, not dose, predicts language.
Kok et al. (2002) used alternating play treatments with preschoolers. They also saw that kids with higher mental age made bigger communication jumps. Together these papers line up: when IQ is low, words stay scarce no matter what we try.
Why it matters
If a preschooler has both autism and intellectual disability, plan for the long haul. Two years may not be enough for phrase speech, and that’s not a service failure. Shift goals to robust augmentative systems early. Start signs, PECS, or SGDs while you keep pushing spoken words. Track cognitive level each year so families get real-world expectations.
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02At a glance
03Original abstract
There is uncertainty about the proportion of children with autism spectrum disorders who do not develop phrase speech during the preschool years. The main purpose of this study was to examine this ratio in a population-based community sample of children. The cohort consisted of 165 children (141 boys, 24 girls) with autism spectrum disorders aged 4-6 years followed longitudinally over 2 years during which time they had received intervention at a specialized autism center. In this study, data collected at the 2-year follow-up were used. Three categories of expressive language were defined: nonverbal, minimally verbal, and phrase speech. Data from the Vineland Adaptive Behavior Scales-II were used to classify expressive language. A secondary objective of the study was to analyze factors that might be linked to verbal ability, namely, child age, cognitive level, autism subtype and severity of core autism symptoms, developmental regression, epilepsy or other medical conditions, and intensity of intervention. The proportion of children who met the criteria for nonverbal, minimally verbal, and phrase speech were 15%, 10%, and 75%, respectively. The single most important factor linked to expressive language was the child's cognitive level, and all children classified as being nonverbal or minimally verbal had intellectual disability.
Autism : the international journal of research and practice, 2015 · doi:10.1177/1362361314556782