Researchers studying pre-school children with autism spectrum disorder found that symptom severity and adaptive functioning varied among the children at diagnosis and changed over time. Medical News Today reports that in a new study, Dr Peter Szatmari and colleagues evaluate the developmental trajectories of these two domains of autism spectrum disorder (ASD). Some differences were observed by the team to increase by the time the children reached the age of 6. Prior to this study, the association between symptom severity and adaptive functioning over time had not been investigated. According to the researchers, current literature on the subject describes ASD as a lifelong condition involving persisting and stable impairments.
A total of 421 newly diagnosed preschool children with ASD participated in the multi-site longitudinal Pathways in ASD Study. The researchers collected data at up to four separate points – from time of diagnosis until the age of 6 – in order to trace the developmental trajectory of each child. Symptom severity was measured using the Autism Diagnostic Observation Schedule (ADOS) and adaptive function was assessed using the Vineland Adaptive Behavior Scales, Second Edition.
The researchers observed two distinct trajectories for symptom severity among the participants. While the majority of the children (88.6%) had severe symptoms and a stable trajectory, 11.4% of the children were found to have less severe symptoms with a trajectory of improvement. The sex of the participants was a predictor of which trajectory group the children were in, with female participants more likely to have less severe symptoms with an improving trajectory.
"Although there is certainly a link (based on cross-sectional correlations) between a child's autistic symptom severity and adaptive functioning at any given point, longitudinal data presented herein suggest that this association is much more complex over time," write the authors.
Only 58.2% of children and families initially approached for the study agreed to participate fully. The authors acknowledge that they cannot be sure that these children are similar to those that successfully participated in the study for its entire duration. Further research is required to assess whether the findings can be generalized.
A limited number of data points also restricts the authors from estimating trajectory curves for the participants over time, although it is hoped that additional assessments currently in progress will address this limitation.
[link url="http://www.medicalnewstoday.com/articles/288731.php"]Full Medical News Today report[/link]
[link url="http://archpsyc.jamanetwork.com/article.aspx?articleid=2091920"]JAMA Psychiatry abstract[/link]