Transdiagnostic and sex differences in cognitive profiles of autism spectrum disorder and attention-deficit/hyperactivity disorder.
Autism versus ADHD cognitive clues flip by sex—check autism quotient in men and verbal-performance IQ gap in women.
01Research in Context
What this study did
Doi et al. (2022) looked at how thinking skills differ in adults with autism and ADHD. They also asked whether these patterns look different in men and women.
The team used WAIS-III sub-tests and machine learning to find the best clues for telling the two diagnoses apart.
What they found
For men, a high autism quotient score was the clearest sign of ASD versus ADHD. For women, the gap between verbal and performance IQ best pointed to ASD.
In short, the same test numbers mean different things depending on sex.
How this fits with other research
Wormald et al. (2019) saw no sex gap on the SRS-2 in high-functioning children. The new study does find sex gaps, but it used adult WAIS-III data, not child SRS-2 scores. Age and tool explain the clash.
Beggiato et al. (2017) warned that the ADI-R can miss girls. Hirokazu’s work adds a second check: look at the verbal-performance split in females.
Gao et al. (2024) showed opposite brain connectivity patterns in male versus female ASD adults. The cognitive split found here lines up with those brain findings.
Why it matters
If you test adults for differential diagnosis, use sex-specific rules. A high autism quotient alone may overlook autistic women. Add the verbal-performance IQ gap to your checklist and you will catch cases that single-score cutoffs miss.
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02At a glance
03Original abstract
An increasing number of studies have shown that autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) share symptoms and aetiologies. However, transdiagnostic comparisons between ASD and ADHD is complicated due to the sex differences within each condition. To clarify the similarities and differences in the cognitive functioning between ASD and ADHD, while considering potential sex differences, this study compared cognitive profiles assessed by the WAIS-III between the four groups created by orthogonally combining diagnosis and sex based on the data from 277 ASD males, 86 ASD females, 99 ADHD males and 64 ADHD females. The analysis revealed three major findings. First, performance IQ and perceptual organization index were higher in ADHD males than in ASD males and ADHD females. Second, Gaussian mixture model fitting revealed two clusters underlying the distribution of subindex scores. The percentage of being classified into the cluster that scored lower in all the subindices was higher in females than in males irrespective of diagnosis. Third, feature importance for classification of ASD and ADHD yielded by random forest classifier, a supervised machine learning algorithm, revealed that autism quotient was most informative feature in classifying ASD and ADHD in males, while the discrepancy between verbal and performance intelligence quotient was in females, indicating that the set of behavioral features contributing to classification differs between males and females. Thus, these findings indicate that sex as well as diagnosis is critical in determining the cognitive profiles of people with ASD and ADHD. LAY SUMMARY: The present study compared profiles of cognitive functions measured by Wechsler Adult Intelligence Scale between males and females with ASD and ADHD. The analyses revealed clear sex differences in cognitive functions in both ASD and ADHD and that the set of cognitive functions useful in classifying ASD and ADHD differed between males and females. Thus, biological sex seems to be a critical factor in determining the cognitive profiles of people with ASD and ADHD.
Autism research : official journal of the International Society for Autism Research, 2022 · doi:10.1002/aur.2712