Abstract
BACKGROUND: The study delves into the intricate task of differentiating intellectual structures among children diagnosed with the high-functioning Autism Spectrum Disorder (HF-ASD), Attention Deficit Hyperactivity Disorder (ADHD), or comorbidity (ASD+ADHD), aiming to assist in their clinical differentiation, with the goal of refining clinical diagnoses and developing targeted therapeutic interventions. METHODS: The study included 200 outpatients aged 6.5-13.0 years (total Intelligence Quotient (IQ) 70-130) at the Children's Hospital of Chongqing Medical University, and categorized into HF-ASD (n=91), ADHD (n=47), and comorbidity ASD+ADHD (n=62) groups. We utilized the Chinese Wechsler Intelligence Scale for Children (C-WISC) as the primary assessment tool, supplemented by additional diagnostic measures. Besides, we used SPSS 25.0 to assess the subtest scores and differences. RESULTS: The comorbidity group had lower total IQ than the other two groups (p<0.001). The verbal IQ(VIQ) were lower than the performance IQ(PIQ) in HF-ASD (p=0.017) and comorbidity (p=0.007) groups. They also scored higher on perceptual organization subtests particularly in Block Design and Object Assembly than the ADHD group. The ADHD group showed higher VIQ than PIQ (p=0.020). The ADHD group's scores for working memory subtests were lower than in the HF-ASD group. The respective peak scores for the HF-ASD and comorbidity groups were in Block Design (45%,43%) and Object Assembly (30%,37%) and valleys in Picture Completion (52%,24%), Information (HF-ASD 24%), and Arithmetic (comorbidity 42%). CONCLUSION: The peak-valley difference in the ADHD group (~2 standard deviations) was smaller than in the HF-ASD and comorbidity groups (~3 standard deviations), and this characteristic could help differentiate between HF-ASD, ADHD, and both together.