1. Screening assessment to determine if a child has ADHD and would be a good candidate to have their ADHD treated with an extended release (ER) stimulant medication. If the answer to step one is yes, then the child will be randomly assigned to receive either medication treatment with an extended release MPH product (OROS MPH). 78% of children with start with this option with 22% assigned to behavioral therapy/counseling treatments for ADHD. There will be no placebo treatments used in this study. All children must be between the ages of 5 and 12 and never have taken stimulant medications for ADHD for more than one week to be eligible for the study.