School dysfunction in youth with autistic spectrum disorder in Taiwan: The effect of subtype and ADHD

School dysfunction is observed in youths with autism spectrum disorder (ASD), but the factors moderating their school dysfunction have not been well explored. This study investigated school functions in youths with ASD in Taiwan, stratified by personal characteristics including demographics, ASD subtypes, intelligence profiles, and the presence of attention‐deficit hyperactivity disorder (ADHD). We recruited 160 youths (aged 6–18 years, 87.5% boys) with a clinical diagnosis of ASD and 160 age and gender‐matched typically developing (TD) youths. Their parents received a semi‐structured psychiatric interview for their ASD and ADHD diagnoses and reported their school functions. Youths with ASD were further grouped into low‐functioning autism (LFA, ASD with intellectual disability and developmental language delay, n = 44), high‐functioning autism (HFA, ASD with no intellectual disability, n = 55) and Asperger's syndrome (AS, ASD with neither language delay nor intellectual disability, n = 61). Compared to TD, ASD had worse school functions in the domains of academic performance, attitude toward schoolwork, social interaction, and behavioral problems except for no academic differences from TD in HFA and ASD without ADHD. Subgroup analysis revealed that HFA and AS had better academic performance but showed worse attitude toward school than LFA. Comorbidity of ADHD negatively impacted all domains of school functions. Besides autistic and ADHD symptoms, oppositional symptoms, lower intelligence, older age, and female gender in youths also predicted school dysfunction. Although youths with ASD have school dysfunction in several domains, this study specifically addresses the role of intelligence and comorbid ADHD on their school dysfunction. Autism Res 2018, 11: 857–869 . © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Lay Summary Impaired school functions varied in ASD youths with different characteristics. Youths with autism spectrum disorder (ASD) encounter varying levels and domains of impaired performance at schools, such as lower academic performance, negative attitude toward school work, fewer reciprocal friendships, and more behavioral problems. Our results indicate that ASD youths without intellectual disability had better academic performance, but worse attitude toward school than those with intellectual disability. Co‐occurrence with ADHD is associated with school dysfunction. In summary, intelligence and comorbid ADHD influences several domains of school functions.