Cognitive profiles of adults with high-functioning autism spectrum disorder and those with attention-deficit/hyperactivity disorder based on the WAIS-III.
WAIS-III subtest highs and lows can help you tell high-functioning ASD from ADHD in adults.
01Research in Context
What this study did
Kanai et al. (2017) gave the adult WAIS-III IQ test to two groups: adults with high-functioning autism and adults with ADHD.
They looked at every subtest score to see if the two diagnoses leave different fingerprints.
What they found
The ASD group scored higher on Information, Arithmetic, and Digit Span.
They scored lower on Picture Completion than the ADHD group.
Verbal IQ minus Performance IQ gaps also differed between the two groups.
How this fits with other research
Kim et al. (2020) saw a similar pattern in Korean boys using the child WISC-IV. ASD boys showed weaker verbal and processing speed scores, while ADHD boys had poorer working memory.
Wilmut et al. (2013) found that many adults with ASD also meet ADHD symptom criteria. Chieko’s work shows the WAIS-III can still separate the two groups despite that overlap.
Nydén et al. (2010) concluded adult ASD and ADHD show only broad, overlapping cognitive weaknesses. Chieko’s finer-grained WAIS-III data contradicts that view and gives clearer diagnostic clues.
Why it matters
If you test adults for differential diagnosis, compare their WAIS-III subtest scatter. A peak on Information and a dip on Picture Completion tilts toward ASD. A flat or reversed pattern tilts toward ADHD. Use these signposts alongside your clinical interview to sharpen your diagnosis and tailor supports.
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02At a glance
03Original abstract
The cognitive profile differences between adult patients with autism spectrum disorder (ASD) and those with attention-deficit/hyperactivity disorder (ADHD) are not well characterized. We examined the cognitive profiles of adults having either ASD (n=120) or ADHD (n=76) with no intellectual disabilities (IQ≥70) using the Wechsler Intelligence Scale III (WAIS-III). Verbal Intelligence (VIQ) - Performance Intelligence (PIQ) difference discrepancies were detected between the two groups. Information subtest scores of the Verbal Comprehension index and Arithmetic and Digit Span subtests of the Freedom from Distractibility index were significantly higher in ASD than in ADHD, while the Picture Completion subtest was significantly lower in ASD. To our knowledge, this is the first study to evaluate the difference in the cognitive profiles of adults with ASD and those with ADHD based on the WAIS III with a large number of participants.
Research in developmental disabilities, 2017 · doi:10.1016/j.ridd.2016.12.008