Inhibitory performance, response speed, intraindividual variability, and response accuracy in ADHD
Patrick de Zeeuw1, Cornelieke Aarnoudse-Moens, Joyce Bijlhout
1Department of Clinical Neuropsychology, VU University Amsterdam, the Netherlands. p.dezeeuw@umcutrecht.nl
Insights
Children with attention-deficit/hyperactivity disorder (ADHD) showed poorer inhibitory performance, response speed, and accuracy than healthy controls. A model combining mean reaction time, intraindividual variability, and errors accurately predicted ADHD diagnosis in 87% of cases.
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.
Objective:
To determine the potential of inhibitory performance, response speed, and response accuracy and variability, measures central to the conceptualization of attention-deficit/hyperactivity disorder (ADHD), in distinguishing children with ADHD from healthy controls (HCs).
Method:
The stop signal paradigm was administered to 38 children with ADHD and 31 NCs. The stop signal reaction time (SSRT), mean reaction time (MRT), intraindividual coefficient of variation (ICV), and number of errors were used to predict diagnostic status.
Results:
Univariate tests showed that the ADHD group performed worse than NCs on all of the dependent variables. Exploratory univariate analyses showed that oppositional defiant disorder comorbidity and ADHD type did not influence results except for the ICV, the effect for this variable (more variability in the ADHD group) being less pronounced for the Predominantly Inattentive type than for the Hyperactive-Impulsive and Combined types. A logistic regression model of the MRT, ICV, and number of errors combined showed best predictive performance, with the MRT contributing the most to group classification (56% of the variance). The final model (MRT, ICV, and number of errors) predicted 87% of the sample in the correct diagnostic category. Operating characteristics showed excellent sensitivity and specificity of 89.5% and 83.9%, respectively.
Conclusions:
Our results contrast with theoretical accounts emphasizing inhibitory control as the pivotal measure characterizing cognitive performance in ADHD. Results are discussed in the context of a delay aversion perspective of ADHD.
