Stability of Symptom Severity and Adaptive Function from Preschool to Elementary Age in Children with Autism Spectrum Disorder

Background:  Autism spectrum disorder (ASD) is a developmental disorder with onset in early childhood, and the individuals diagnosed with ASD would persist in their life course. Literature in the West countries has demonstrated that as they grow up to school age or adolescent, the autistic symptom severity and adaptive behavior may improve. However, there was no report in Taiwan, a country in the East.

Objectives:  The purpose of this study was to examine the stability of symptom severity and adaptive behavior from toddler to school age in the children with ASD.

Methods:  Twenty seven children diagnosed with ASD between 42 and 64 months of age (at mean age of 48 months) (Time 1, T1) were followed after 3.5 years (Time 2, T2). Autism Diagnostic Interview-Revised (ADI-R) was used to measure autistic symptom severity, and Vineland Adaptive Behavior Scales-Ⅱ(VABS-Ⅱ) was used to measure daily adaptive behavior. All of the children were diagnosed with DSM-IV in a multidisciplinary team including child psychiatrist, child psychologist and pediatrician at two time point.

Results:  First, the symptom severity score at T1 was compared with the score at T2. The results indicated that the symptom severity score varied by different domains at T2. The ADI-R scores of verbal-communication domain (p = .014), repetitive and stereotyped behavior domain (p = .021) and total score (p = .049) were decreased at T2, while reciprocal social interaction domain was also declined but no significant difference. The logistic regression analysis found that the diagnosis score of ADI-R at T1 could predict the clinical diagnosis at T2 (p = .00). Second, the adaptive behavior score also varied by different domain. The VABS-II standard score of social domain was reduced (p=.019) but the age equivalent was increased (p= .00) at T2; the standard score of other domains were no significant difference between the two time point but all age equivalent were improved at T2. Finally, there was no significant correlation between domains of ADI-R score and VABS-II scores.

Conclusions:  This study manifested that as children with ASD grows up, the social deficit would still persist. Although these children with ASD developed some of  adaptive behaviors in the school age, the magnitude of improvement couldn’t equal to the change of their chronological age. Future studies should be continued to follow these sample to learn the long-term trajectory of symptom severity and social adaptation.