To investigate the final dosage of OROS-methylphenidate for patients achieving optimal response in 10 weeks.The optimal response is defined as a score of 0 or 1 on each of the first 18 ADHD items (referred to SNAP-IV (Swanson, Nolan and Pelham)) [clinicaltrials_resource:223ca0080f7afcc3d219973a66522347]

To investigate the final dosage of OROS-methylphenidate for patients achieving optimal response in 10 weeks.The optimal response is defined as a score of 0 or 1 on each of the first 18 ADHD items (referred to SNAP-IV (Swanson, Nolan and Pelham)) [clinicaltrials_resource:223ca0080f7afcc3d219973a66522347]