To clarify the pathophysiological background of attention deficit/hyperactivity disorder (AD/HD) and its comorbidity with oppositional defiant/conduct disorder (ODD/CD) neuropsychological and electrophysiological correlates were investigated. AD/HD cannot be fully explained by an inhibition-specific deficit. Impairments of attentional orienting, response preparation, and response execution processes are implicated as well. Motor response control was particularly impaired in AD/HD+ODD/CD, while ...