Extended periods of participation in speech and language therapies can significantly aid most autistic children in developing their first words, according to a recent study. Autism spectrum disorder, which impacts one in 31 children in the United States, frequently presents challenges with speech, leading many affected children to be nonverbal or to acquire speech much later than their neurotypical counterparts. Historically, autistic children experiencing speech difficulties have shown positive responses to intensive therapies, verbal speech exercises, and assistive devices during their early education years.

A new study from Drexel University in Philadelphia provides compelling evidence that speech language therapies are not only effective, but also that approximately two out of three autistic children are likely to learn to speak through these interventions. Researchers examined data from over 700 preschoolers with autism spectrum disorder who underwent speech intervention therapies for durations ranging from six months to two years, typically spending about 10 hours per week in therapy. The findings revealed that two-thirds of the children in the study developed spoken language, while the remaining one-third either remained nonverbal or showed no progress.

The experts attribute these improvements in speaking abilities to various therapeutic approaches. Among those mentioned are the Early Start Denver Model (EDSM), which emphasizes play and fostering positive relationships to enhance language skills, and the Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH) therapy, which employs visual cues, organized spaces, and structured schedules to boost speech. Other methods included Naturalistic Developmental Behavioral Interventions, which are play-based and child-initiated, and Early Intensive Behavioral Intervention (EIBI), typically a one-on-one therapy targeting social and daily living skills.

A crucial insight from the Drexel team is that the *duration* of therapy, rather than its intensity, was associated with better outcomes for nonverbal children. This implies that sustained therapy over several months or years, even at a moderate commitment of around 10 hours per week, may be more beneficial than shorter, highly intensive regimens of 20 to 40 hours per week. Dr. Giacomo Vivanti, a study author and associate professor at the AJ Drexel Autism Institute, reaffirmed the value of these interventions, stating, "When parents ask me if their child should do these interventions to gain spoken language, the answer after doing this study is still yes." He also emphasized the importance of monitoring each child's response to therapy, noting, "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."

The study, published in 2025 in the Journal of Clinical Child & Adolescent Psychology, evaluated 707 autistic children aged between 15 months and five years, with an average age of three. At the study's baseline, 66 percent of participants were categorized as 'minimally speaking,' meaning they could not combine words into short phrases. Of the participants, 216 were enrolled in ESDM, 208 in Naturalistic Developmental Behavioral Interventions, 197 in EIBI, and 86 in TEACCH.

Regarding outcomes, 66 percent of children who were initially non-speaking at the beginning of the study progressed to learning single words or advancing their language abilities by the end of their therapies. For those who were minimally speaking at baseline, 50 percent advanced to being able to combine words into phrases. However, one-third of children who started out non-speaking remained non-speaking after two years, and half of the minimally speaking group did not advance. The researchers observed that children who did not advance typically engaged in therapy for shorter durations, such as under six months, often with more hours per day, further reinforcing the importance of sustained, longer-term engagement. Conversely, children participating in therapy for six months to two years showed a higher likelihood of language gains.

Furthermore, the study found that children who demonstrated greater ability to imitate sounds and actions at the start of the study had a higher probability of advancing their language skills. Dr. Vivanti explained this correlation, suggesting, "Those nonspeaking prerequisites of communication may help create infrastructure for spoken language. Imitating what others are doing may help may them later to imitate what people are saying, and from there using language to express their thoughts."

The study acknowledged several limitations, including following children for a maximum of two years, but the team suggested that this research could pave the way for more comprehensive future studies. Dr. Vivanti highlighted the collaborative spirit within the early intervention community, stating, "This paper shows a willingness in the early intervention community to collaborate on data and learn more about how to help all children."

In a broader context, recent CDC data indicates an increase in autism diagnoses, with one in 31 US children currently affected, compared to about one in 150 in the early 2000s. While the exact reasons for this surge remain unclear, theories range from environmental factors such as mold, pesticides, food additives, medications, or ultrasounds, as suggested by Robert F Kennedy Jr, to improved diagnostic capabilities among doctors, particularly in recognizing the condition in previously overlooked groups like girls and adults.