1) ADHD involves dysfunction in several brain networks and connections rather than a single brain region. Functional neuroimaging has shown that tasks like response inhibition involve the coordinated activity of frontal, parietal, and striatal regions rather than just the frontal lobe. 2) Studies have identified distinct brain networks associated with successful response inhibition and errors of commission, showing that response control is not localized to one area. 3) Current diagnostic criteria and neuropsychological tests do not adequately assess the underlying neural networks and interactions involved in ADHD symptoms. Bridging functional neuroimaging and neuropsychological assessment may help establish better diagnostic methods.