- Children being treated with other stimulant or non-stimulant medications prior to enrollment will be allowed to discontinue treatment with these medications in order to enter the study, providing the parent wants to do so to enable their child to have a trial of Ritalin LA, the target symptoms are not well-controlled or unwanted side effects are persisting on their current treatment, and the prescribing physician is notified by the parent. These children will have a visit 1A in order to accommodate a 5 half-lives washout of their pre-study medication.