The Effects of Methylphenidate on Cognitive Function in Children with Attention–Deficit/Hyperactivity Disorder

Abstract

Focusing on behavioral criteria for attention–deficit/hyperactivity disorder (ADHD) diagnosis leads to considerable neuropsychological profile heterogeneity among diagnosed children, as well as variable response to methylphenidate (MPH) treatment. Documenting “cold” executive working memory (EWM) or “hot” self–regulation (SR) neuropsychological impairments could aid in the differential diagnosis of ADHD subtypes and may help to determine the optimal MPH treatment dose. In this study, children with ADHD inattentive type (n = 19), combined type (n = 33), and hyperactive–impulse type (n = 4) underwent randomized controlled MPH trials; neuropsychological, behavioral, and observational data were collected to evaluate the children's responses. Those with moderate or significant baseline EWM/SR impairment showed robust MPH response, whereas response for those with lower baseline impairment was equivocal. Implications for medication use and titration, academic achievement, and long–term treatment efficacy are examined.