Youth with ADHD, autism or comorbid ADHD and autism in Iceland: Comparisons of attentional and cognitive profiles and the effects of anxiety on cognitive performance.

Researchers studied thinking and attention skills in 872 children with ADHD, autism, or both from Iceland. They found that children with both ADHD and autism had different strengths and challenges compared to children with just one condition. Children with ADHD showed more ups and downs in their attention. When children also had anxiety, it affected their verbal skills but actually helped their focus on some tasks.

This shows that every child's profile is unique and needs different support approaches.

This large Icelandic study examined cognitive and attentional profiles in 872 youth aged 7-18 with ADHD, autism, or both conditions. Using standardized assessments (WISC-IV and CPT-3), researchers found that youth with comorbid ADHD and autism showed better perceptual reasoning than those with ADHD alone, but similar performance to autism-only groups. Children with ADHD demonstrated greater performance variability on attention tasks compared to other groups. Notably, anxiety disorders impacted cognitive performance differently across domains - reducing verbal comprehension scores but improving sustained attention performance.

These findings highlight the complexity of cognitive profiles in neurodivergent youth and emphasize the need for individualized assessment and accommodation strategies in clinical and educational settings.

Results support individualized cognitive assessment approaches for neurodivergent youth. Clinicians should consider comorbidity patterns when planning interventions and accommodations. The complex effects of anxiety on different cognitive domains suggest need for comprehensive anxiety assessment and targeted management strategies in neurodevelopmental conditions.

Study design is not specified in the abstract. While the sample is large and nationwide, it relies on clinical records from one assessment center. The cross-sectional nature limits understanding of developmental trajectories. Generalizability beyond Iceland may be limited due to cultural and healthcare system differences.

Attentional and cognitive profiles of youth diagnosed with attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), or co-occurring ADHD and ASD were examined in a large, nationwide clinical sample in Iceland. The impact of anxiety disorders on cognitive performance in this neurodiverse sample was also examined. Clinical medical records at a government-run assessment center serving youth from all of Iceland comprised the study sample of 872 youth aged 7-18 years. All participants had been diagnosed with ADHD, ASD, or ADHD+ASD without intellectual impairment; of these, 239 youth were also diagnosed with co-occurring anxiety.

All participants completed the Wechsler´s Intelligence Scale for Children-Fourth Edition (WISC-IV) and the Conners Continuous Performance Test 3rd Edition (CPT-3) as part of their diagnostic process. Results indicated that children with ADHD+ASD performed better on the Perceptual Reasoning Index (PRI) on the WISC-IV compared with children with ADHD but showed no difference compared to the ASD only group. On the CPT, differences emerged for children with ADHD, who showed more variability in their performance compared with children with ASD or ADHD+ASD. Children with neurodevelopmental disorders (ADHD and/or ASD) and a co-occurring anxiety disorder performed worse on the Verbal Comprehension Index (VCI) on the WISC-IV.

Still, they performed better on the CPT compared with children with neurodevelopmental disorders without anxiety. The findings reveal patterns of cognitive performance for children with ASD and/or ADHD with co-occurring anxiety disorders that need to be considered for appropriate accommodation in clinical, teaching and testing approaches for neurodiverse children.