Inhibitory control deficits in children and adolescents with ADHD: A comparative study

Although Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by complex inhibitory deficits, generalized interventions often show poor patient engagement and adherence. This study compared domain-specific inhibitory control in children and adolescents with ADHD to characterize the precise nature of these deficits.

A cross-sectional comparative design was used with 146 participants, comprising 82 children (aged 9-11) and 64 adolescents (aged 16-18), including both ADHD and typically developing groups. Participants completed three computerized paradigms targeting distinct inhibitory subdomains: The Stroop Color-Word Test (interference control), the Cued Go/No-Go Task (proactive and reactive control; action restraint), and the Stop-Signal Task (reactive inhibition, action cancellation).

A significant neurocognitive dissociation emerged. Interference control (Stroop performance) was selectively preserved in the ADHD group: latency did not differ from TD peers, but response accuracy under interference was significantly reduced. In contrast, youth with ADHD showed pronounced reactive inhibition deficits on both the Cued Go/No-Go and Stop-Signal tasks, reflected in significantly slower reaction times and longer Stop-Signal Reaction Times. As a supplementary finding, proactive inhibitory control did not differ between groups, indicating relatively preserved proactive control in ADHD. Significant main effects of group and age emerged for most inhibitory control measures, with no significant Group × Age interactions.

The selective impairment of reactive inhibition (both action restraint and action cancellation), together with selectively preserved (latency-based but not accuracy-based) interference control, challenges the utility of "one-size-fits-all" cognitive training. The comparatively spared proactive inhibition further supports a domain-specific, rather than global, account of inhibitory dysfunction in ADHD. These findings underscore the need for targeted, process- and parameter-specific intervention approaches that precisely target motor inhibition rather than broad attentional filtering.