Impairment in flexible regulation of speed and accuracy in children with ADHD

Attention deficit hyperactivity disorder (ADHD) is characterized by poor adaptation of behavior to environmental demands, including difficulties in flexibly regulating behavior. To understand whether ADHD is associated with a reduction of strategic flexibility in modulating speed and accuracy, we used a perceptual decision-making task that required participants to randomly stress either fast or accurate responding. Thirty-one drug-free boys with ADHD combined-type (mean age: 10.2 years) and 33 healthy control boys (mean age: 10.7 years), matched for age and IQ, participated. Both reaction time and accuracy data were analyzed. Our findings demonstrated significantly lower accuracy in ADHD children than in controls when switching from speed to accuracy instructions. This deficit was directly associated with hyperactivity symptoms but not with inattention. Our results showed that ADHD is associated with a deficit in dynamically switching response strategy according to task demands on a trial-to-trial basis.