EEG correlates of methylphenidate response in ADHD: association with cognitive and behavioral measures

The authors examined the association between EEG correlates of medication response and concomitant cognitive and behavioral changes among children with attention-deficit hyperactivity disorder (ADHD). Subjects were 36 children with ADHD, aged 8 to 12 years. EEG activity was recorded from nine active electrodes during placebo and medication conditions. Medication administration resulted in increased alpha activity in central and parietal regions during both the baseline and cognitive activation conditions. Children who were medication responders exhibited increased frontal beta activity whereas nonresponders showed decreased beta activity in the same region. Increased frontal beta activity was significantly correlated with medication-related improvement in performance on Conners'Continuous Performance Test and parent behavior ratings in attention and hyperactivity. Decreased right frontal theta activity was associated with improvements in parent-rated attention, but not in CPT performance. Stimulant medication increases beta activity in children with ADHD, particularly in frontal regions. Increased cortical arousal and activation in the frontal cortex is strongly associated with sustained attention and response inhibition and with parent-rated attention and hyperactivity/impulsivity.