A recent investigation published in the renowned journal Pediatrics, revealed that 70% of children diagnosed with autism spectrum disorders (ASD) who have a history of severe language delay can achieve sentences or fluent speech by the age of 8. These results suggest that 4-year-old children with severe language delays can show significant improvements in language. These results have important implications for both therapeutic purposes and future research on the topic.
The study
The research used the largest sample to date to examine the relationship between key deficits associated with ASD and the attainment of fluent expression or speech after a severe language delay. As a common milestone in speech development, a sentence is defined as the use of uncopied, three-word utterances, sometimes containing a verb, and are spontaneous and meaningful; while fluent speech is characterized as the ability to use complex expressions to talk about topics outside the immediate physical context.
“We found that nonverbal intelligence was the most important predictor of sentence construction, while social interest and engagement were as important, or even more so, in predicting the age at which children reach sentences and fluent speech in language development,” she said. Dr. Ericka L. Wodka, a neuropsychologist at the Center for Autism and Related Disorders (Center for Autism and Related Disorders) of the Kennedy Krieger and lead author of the study. “Children with average nonverbal intelligence achieved language almost six months earlier than those with below-average scores.”
These findings reinforce that basic skills, such as nonverbal intelligence and social engagement, have a greater influence on communication development than other behaviors associated with ASD, such as repetitions and abnormal sensory behaviors. “Our findings continue to support the importance of considering both nonverbal intelligence and social communication when planning treatment, highlighting the differential impacts of these factors in relation to treatment goals,” says Dr. Wodka.
The instruments
The data for this retrospective study were drawn from the Simon Simplex Collection(SSC), a unique multi-site database project, brings together biological and phenotypic data from children with ASD between the ages of four and eighteen years with no prior genetic history of ASD. The database establishes a permanent repository of samples from 2,700 families, each with an affected child and unaffected parents and siblings.
From the SSC, a total of 535 children, aged eight years and older, were selected for the study. Using the Autism Diagnostic Interview-Revised (ADI-R Autism Diagnostic Interview, revised version), a standardized interview for parents that distinguishes children with ASD from the population without these disorders, and the Austism Diagnosis Observation Schedule (ADOS, Autism Diagnostic Observation Scale), a therapist-administered observation that assesses social, communicative, and stereotyped behaviors, researchers selected children who either had not developed the ability to construct sentences at the time they enrolled in the SSC, or whose sentence development began after the age of four.
Based on their ADI-R scores and language presentation, children in this study were administered one of four assessment modules: no words or single words (Module 1), phrases (Module 2), or fluent speech (Module 3 or 4). Of the 535 study participants, 119 had mastered phrases and 253 were fluent by age 8, while 163 never reached phrases or fluent speech.
Implications for treatments and future research
“We hope the results of this study will help parents of children with autism and severe language delays know that, with appropriate therapy, a child is likely to make significant progress in this area over time; however, expectations for progress should be lower for children with lower intellectual abilities,” says Dr. Wodka. “Additionally, we hope these findings will provide professionals with better and more defined therapeutic goals for their patients with autism.”
Future longitudinal studies, including both single and multiple families, are needed to fully capture the prevalence and predictors of language development in children with ASD. Furthermore, future studies on the impact of social cognitive strategies (e.g., perspective-taking) on language development, as well as the relationship between specific social deficits and the development of fluent speech, may have important implications for intervention design.
Fountain: Kennedy Krieger Institute