Risk Factors Associated with Language in Children with Autism Spectrum Disorder
by Wendy Hoke
Identifying risk factors related to neurodevelopmental disorders represents a crucial line of research, as it can promote earlier identification of children who might benefit from specific interventions supporting better developmental outcomes. Recently, an article in the Journal of Speech, Language and Hearing Research reviewed research focused on risk factors related to Autism Spectrum Disorder (ASD). Published in February 2016, the author focused on studies of infants who had siblings diagnosed with ASD, with the specific emphasis on risk factors related to language deficits that typically impact a majority of children with ASD.
The research reviewed addressed a variety risk factors including demographic markets, neural risk markets, and behavioral markers. The purpose of the study was to identify risk factors related to neurodevelopmental disorders and to summarize the research pertaining to language as a risk factor in ASD.
Language in Autism Spectrum Disorder
In the DSM-5, impaired or delayed language is no longer listed as a core symptom of ASD, although clinicians and service providers must continue to note if a child with ASD has a comorbid language disorder. Considerable variability exists among the language profiles of these children. Some have structural language skills with scores in or above the normal range using standardized language testing. Some children acquire spoken language skills after some delays in onset, although they do not ultimately reach the normal range, and some children never acquire fully functional language skills, even if they have access to competent, early interventions. These children are known as minimally verbal; however, evidence about the source of the language deficits remains unknown. Estimates of the percentages of the subgroups tends to vary according to the assessment methods, but the majority of children with ASD acquire language skills but remain delayed in relation to their peers. Some researchers have suggested that this group that has ASD with some language impairment has a comorbid specific language impairment (SLI), although controversy exists concerning this assertion.
The early developmental profiles relating to language in autism spectrum disorder are significantly varied. Most children have delays in standard milestones, particularly the onset of words and phrases. According to standardized measurements, receptive language seems to be more impaired than the child’s expressive language; however, this may be due to a deficit in social responsiveness rather than language processing impairments. After showing early delays, some children experience accelerated language development around ages three and four, thereby no longer meeting the criteria for a language delay. Other children experience language regression. At 12 to 15 months in age, they may start to use words, but later in their second year they stop using those skills and no longer speak. The loss of social and language skills marks the onset of autism spectrum disorder. As they grow older, some children will gain back some language skills, while other will not.
The author noted that the studies reviewed showed that effective early behavioral intervention was a critical influence on language development in children with ASD. In fact, several studies that assessed different methods of behavioral interventions showed the most gains in both receptive and expressive language. For instance, one study found that toddlers who received a comprehensive behavioral intervention for 20 hours per week showed a gain of nearly 12 points for expressive language and 20 points for receptive language after 24 months in the program. Other studies found that shorter, highly targeted interventions could also lead to greater gains in language skills, such as one study that training toddlers and preschoolers in joint attention skills for 30 minutes per day resulted in gains in expressive language after 6 weeks and continued after several years after the program was administered. In each study reviewed, some children made little to no progress; however, the predictors to the responses remained unidentified. Thus, in ASD there is considerable variation in language as reflected in response to treatment, developmental trajectories, and long-term outcomes.
Language skills continue to be a critical predictor of long-term social, educational and vocational success for all children, but especially those with ASD. Thus, understanding the complete range of risk factors that can predict language deficits is important because it will allow clinicians and other professionals to identify children who would benefit from targeted interventions at an earlier age prior to a language disorder is diagnosed. Although a great deal of progress has been made at pinpointing risk factors for language in Autism Spectrum Disorder, more attention should be given to SLI, especially since SLI impacts more children than ASD.
Another conclusion drawn from the review of literature was that both SLI and ASD share many of the same risk factors, and this risk factors may extend to a variety of neurodevelopmental disorders that have unknown etiologies. In addition, it appeared that risk factors can be identified at the levels of brains, genes, behavior and environment. No one factor could be singled out, rather it appeared that a cumulative, complex model of risk factors is the most likely approach to developing a complete understanding of the interaction of all potential risk factors impact the language outcomes. Future research may build on the achievements already made, and cross-syndrome analysis could be critical for finding distinct and shared risk factors. The ultimate objective is to design preventive interventions for each individual’s unique cluster of risk factors to offer the best opportunity to achieve full language potential.
Relias Academy offers a number of resources for BCBAs, RBTs, educators and parents looking to learn more about how to support a toddler struggling with language development. A few courses offered about this topic are Activities For Preschoolers: Supporting Language Development, Receptive Language / Listener Responding and Teaching Expressive Language/Tacts.