Comparison of the K-WISC-IV profiles of boys with autism spectrum disorder and attention-deficit/hyperactivity disorder.
K-WISC-IV index gaps give quick clues: autism flags are low verbal and slow processing; ADHD flags are low working memory and poor graphomotor speed.
01Research in Context
What this study did
Kim et al. (2020) gave the Korean WISC-IV to boys with autism and boys with ADHD.
They compared index scores to see if each group shows its own pattern.
No teaching was done; the goal was clearer diagnosis through test data.
What they found
Boys with autism scored lower on Verbal Comprehension and Processing Speed.
Boys with ADHD scored lower on Working Memory and graphomotor tasks.
The two groups leave different "fingerprints" on the same test.
How this fits with other research
Mayes et al. (2008) saw the same low Processing Speed in autism years earlier.
Kanai et al. (2017) extended the idea to adults and found a similar verbal dip.
Ingadottir et al. (2025) looked at kids with both autism and ADHD; they scored higher on perceptual reasoning than ADHD-only kids, adding a new twist.
Toffalini et al. (2022) warns that ADHD profiles look like learning disorder profiles, so always check more than just the WISC before you decide.
Why it matters
Use these index gaps as red flags, not verdicts. Low verbal plus slow processing hints at autism. Low working memory plus messy pencil work hints at ADHD. When both areas dip, think combo. Always pair test data with interviews and direct observation before you label or plan treatment.
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02At a glance
03Original abstract
AIMS: This study aimed to compare the intelligence profiles of children with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) using the Korean Wechsler Intelligence Scale for Children-Fourth Edition (K-WISC-IV) scores to differentiate between their cognitive characteristics. METHODS: Subjects were boys with ASD (n = 49) and ADHD (n = 44). The index and subtest scores of the ASD and ADHD groups were compared using MANOVA. Repeated-measures ANOVA was performed to investigate the cognitive strengths and weaknesses within the ASD and ADHD groups. RESULTS: Verbal comprehension was significantly lower in the ASD group compared to the ADHD group. The ASD group also scored lower than the ADHD group on Vocabulary, Comprehension, Picture Concepts, Picture Completion, and Symbol Search. The ADHD group scored lower than the ASD group on Digit Span. The ASD group displayed slower processing speed and social judgment, while the ADHD group exhibited poor working memory and graphomotor processing. CONCLUSION: The WISC-IV profiles might help distinguishing between the cognitive characteristics of ASD and ADHD boys.
Research in developmental disabilities, 2020 · doi:10.1016/j.ridd.2019.103539