Source-level connectivity and alpha dynamics across attention-deficit hyperactivity disorder (ADHD) clinical presentations

The present research integrated source-localized power envelope connectivity (PEC) with sensor-level individualized alpha frequency (IAF) analysis to identify group-level neurophysiological features that differ between the combined presentation attention deficit hyperactivity disorder (ADHD-C) and the predominantly inattentive presentation (ADHD-I) of ADHD. A total of 99 children with ADHD (46 ADHD-I, 53 ADHD-C) and 19 typically developing children were recruited for the study, with resting-state electroencephalogram (EEG) data collected from all participants. Source-level analyses showed that differences between ADHD presentations were mainly localized within alpha-band networks, particularly in fronto-occipital, frontoparietal, and attention-related circuits. These effects were frequency-specific and state-dependent, rather than reflecting global connectivity alterations. Sensor-level analyses further revealed differences in alpha-band characteristics between ADHD-I and ADHD-C. Compared with ADHD-I, ADHD-C showed higher parietal individualized alpha peak frequency. Correlation analyses indicated that lower alpha frequency was associated with higher hyperactivity-impulsivity scores in the ADHD-I group. In addition, both presentations exhibited reduced alpha power relative to typically developing controls. These findings highlight regionally distributed differences in alpha oscillatory dynamics between clinically defined ADHD presentations. Overall, the findings indicate that ADHD-I and ADHD-C differ in the organization and modulation of alpha-band networks across resting states, supporting frequency- and network-specific neurophysiological differences between ADHD presentations.