Summary: New research reports that approximately two-thirds of initially non-speaking children with autism develop spoken language following evidence-based early intervention. The study identifies key factors, such as intervention duration and motor imitation skills, that influence success.
Key Facts
- Success Rates: Approximately 67% of initially non-speaking children with autism developed spoken language after early intervention.
- Duration vs. Intensity: The study found that the total duration of therapy (months or years) was a more significant predictor of success than weekly intensity (hours per week).
- Critical Skills: Children with stronger motor imitation skills—like clapping or nodding—were more likely to acquire language.
- Study Scope: Researchers analyzed data from 707 autistic preschoolers across various evidence-based intervention programs.
Source: Drexel University
After receiving evidence-based early interventions, roughly two-thirds of non-speaking children with autism speak single words, and approximately half develop more complex language, according to a new study led by researchers at Drexel University’s A.J. Drexel Autism Institute.
The findings, published in the Journal of Clinical Child and Adolescent Psychology, offer vital insights into improving success rates for children who remain non-speaking or minimally speaking after therapy.
With one in 31 children in the United States diagnosed as autistic, and approximately one-third of them estimated to be non-speaking, language skills remain a primary target for early child development. Children who do not gain spoken language beyond the preschool years are often at increased risk for disabilities later in life.
Duration Over Intensity
In the first large-scale study of its kind, the team analyzed data from 707 autistic preschoolers across multiple studies. These children completed various evidence-based early interventions (such as Early Start Denver Model and TEACCH) for at least 10 hours per week.
The researchers found that the duration of the intervention was more strongly associated with positive outcomes than the intensity.
“The researchers found that duration of the intervention, rather than intensity of the intervention, was associated with outcomes in the children who are nonverbal,” the study authors noted.
This suggests that rather than packing 20-40 hours of therapy into a single week, greater success might be achieved by extending therapy over a longer term, providing more opportunities to practice skills.
Monitoring and Adjusting Therapy
Participants who did not see success started with lower scores in cognitive, social, adaptive, and motor imitation measures. However, the study emphasizes that intervention factors are modifiable.
“When parents ask me if their child should do these interventions to gain spoken language, the answer after doing this study is still yes,” said Giacomo Vivanti, PhD, an associate professor at Drexel’s Dornsife School of Public Health.
“What our study is telling us is that even when we’re implementing practices that are evidence-based, some children remain behind. So, we should carefully monitor the response of each child and see what to add or change to tailor therapy for the individual as needed.”
Vivanti emphasized that for some children, the “standard” version of an intervention is sufficient, while others may require a focus on preverbal skills foundational to communication.
Motor Imitation as a Predictor
Consistent with earlier studies, the researchers found that children who engaged in more motor imitation—such as clapping hands or nodding when prompted—were more likely to acquire spoken language.
“Those nonspeaking prerequisites of communication may help create infrastructure for spoken language,” Vivanti explained. “Imitating what others are doing may help them later to imitate what people are saying, and from there using language to express their thoughts.”
Despite the differences in theoretical orientation among the various interventions studied, the specific type of intervention made little difference in language learning outcomes. The study represents a rare large-scale collaboration among autism research institutions to share data on children who do not show optimal responses to established interventions.
Editorial Notes:
- This article was edited by a Neuroscience News editor.
- Journal paper reviewed in full.
- Additional context added by our staff.
About this autism research news
Author: Greg Richter
Source: Drexel University
Contact: Greg Richter – Drexel University
Image: The image is credited to Neuroscience News
Original Research: Closed access.
“Proportion and Profile of Autistic Children Not Acquiring Spoken Language Despite Receiving Evidence-Based Early Interventions” by Giacomo Vivanti et al. Journal of Clinical Child and Adolescent Psychology
Funding: This work was supported by funding from the National Institute on Deafness and Other Communication Disorders.
Abstract
Proportion and Profile of Autistic Children Not Acquiring Spoken Language Despite Receiving Evidence-Based Early Interventions
Objective
To estimate the proportion of autistic children who do not acquire spoken language despite receiving evidence-based early interventions and to identify child and intervention characteristics associated with this outcome.
Method
We pooled data from 707 autistic preschoolers (M age = 30.6 months) participating in studies of evidence-based early interventions. We examined the proportion of children who remained non-speaking or minimally speaking post-intervention and analyzed predictors of language outcomes including cognitive, social, and motor skills, as well as intervention duration and intensity.
Results
Approximately two-thirds of initially non-speaking children acquired single words, and half developed phrase speech. Children who did not acquire spoken language had lower baseline scores in cognition, social affect, and motor imitation. Longer duration of intervention was associated with better language outcomes, whereas intervention intensity (hours per week) was not.
Conclusion
While most children benefit from early intervention, a subgroup remains non-speaking. Monitoring progress and adjusting intervention strategies, particularly duration and focus on preverbal skills like imitation, is critical for supporting these children.
