EEG differences between good and poor responders to methylphenidate in boys with the inattentive type of attention-deficit/hyperactivity disorder

Objectives: This study investigated electroencephalographic (EEG) differences between good and poor responders to methylphenidate in boys with the Inattentive type of Attention-Deficit/Hyperactivity Disorder (ADHD). Methods: Twenty good and 15 poor responders to methylphenidate, based on the results of a continuous performance task, and 35 age- and sex-matched control subjects, participated in this study. EEG was recorded from 21 sites during an eyes-closed resting condition and Fourier transformed to provide estimates for total power, and absolute and relative power in the delta, theta, alpha and beta bands, and for the theta/alpha and theta/beta ratios. Results: EEG differences were found between the ADHD children and controls which were compatible with previous literature on the Inattentive type. Differences were also found between the good and poor responders to methylphenidate. Conclusions: Good responders had EEG profiles that suggested that they were more cortically hypoaroused than poor responders.