Inhibitory performance, response speed, intraindividual variability, and response accuracy in ADHD.

Area of Science:

• Neuroscience
• Child Psychology
• Cognitive Science

Background:

• Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention and/or hyperactivity-impulsivity.
• Cognitive deficits, particularly in inhibitory control, are central to ADHD conceptualization.
• Distinguishing ADHD from healthy controls (HCs) using cognitive measures is crucial for diagnosis and understanding the disorder.

Purpose of the Study:

• To evaluate the diagnostic potential of inhibitory performance, response speed, accuracy, and variability in differentiating children with ADHD from HCs.
• To identify which cognitive measures are most effective in predicting ADHD diagnosis.

Main Methods:

• The stop-signal paradigm was used to assess cognitive performance in 38 children with ADHD and 31 HCs.
• Key measures included stop-signal reaction time (SSRT), mean reaction time (MRT), intraindividual coefficient of variation (ICV), and error rates.
• Logistic regression analysis was employed to predict diagnostic status based on these measures.

Main Results:

• Children with ADHD exhibited significantly poorer performance across all cognitive measures compared to HCs.
• A logistic regression model incorporating MRT, ICV, and errors achieved 87% accuracy in classifying participants.
• The MRT was the most significant predictor, contributing 56% to group classification, with excellent sensitivity (89.5%) and specificity (83.9%).

Conclusions:

• Cognitive performance deficits, particularly in response speed and variability, are significant in ADHD, but inhibitory control alone may not be the sole defining characteristic.
• The findings support a delay aversion perspective in understanding ADHD cognitive profiles.
• The developed model demonstrates high potential for aiding in the objective diagnosis of ADHD.