Working Memory Profiles in Children with ADHD: Differences Between ADHD-I, ADHD-C, and Typically Developing Children

Background: Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by significant working memory (WM) deficits. However, cognitive differences between the predominantly inattentive (ADHD-I) and combined (ADHD-C) presentations require further investigation based on Baddeley's multi-component model. Objective: This study compared WM profiles in children with ADHD-I, ADHD-C, and typically developing (TD) children to identify subtype-specific cognitive signatures and discuss clinical implications. Method: Participants included ۱۳۷ children (۴۱ ADHD-I, ۴۵ ADHD-C, ۵۱ TD) aged ۷–۱۲ recruited from clinics in Tehran, Iran, using convenience sampling. Diagnosis was confirmed via DSM-۵ criteria and the IVA-۲ test. WM components were assessed using the Working Memory Test Battery for Children (WMTB-C). Data were analyzed using one-way ANOVA with post-hoc tests. Results: Both ADHD groups showed significant impairments across all WM components compared to TD children. For the phonological loop and visuospatial sketchpad, no significant differences were found between ADHD-I and ADHD-C. However, for the central executive component, the ADHD-C group performed significantly worse than the ADHD-I group (p < .۰۱). Conclusion: While WM impairments are widespread in ADHD, the central executive is more severely affected in the combined presentation. These findings suggest distinct cognitive profiles for ADHD subtypes, highlighting the need for tailored interventions targeting executive functions in ADHD-C. However, due to the cross-sectional design and clinic-based sample, causal inferences and generalizability are limited. Future longitudinal and neuroimaging studies are warranted to confirm these findings and inform clinical practice.

کلیدواژه ها:

working memory ، Attention-Deficit/Hyperactivity Disorder (ADHD) ، ADHD-I ، ADHD-C ، Childhood