Evaluate the Safety and Efficacy of Methylphenidate Transdermal System (MTS) in Adolescents Aged 13-17 Years With ADHD

Inclusion Criteria: To be eligible for inclusion, each subject must fulfill each of the following criteria at the Entry visit: * The subject participated in the antecedent SPD485-409 study, and a) completed all required study visits (Baseline through Visit 9) OR b) completed the 5 week Dose Optimization period without achieving an acceptable condition as defined by the antecedent SPD485-409 study. * Subject has blood pressure measurements within the 95th percentile for age, gender, and height at Entry. * Subject's ECG results are within the normal range or not clinically significant at Entry as judged by the Investigator in conjunction with the central reader. * Females must have a negative urine pregnancy test at Entry and agree to use acceptable contraceptives throughout the study period and for 30 days the last dose of IP. * Subject and parent of legally authorized representative (LAR) are able, willing and likely to fully comply with study procedures and restrictions. * Written, signed and dated informed consent to participate in the study must be given by the subject's parent or LAR, in accordance with the International Conference on Harmonisation (ICH), Good Clinical Practices (GCP) Guideline E6 and applicable regulations, before completing any study-related procedures. * There must be documentation of the subject's assent to participate in the study indicating that the subject is aware of the investigational nature of the study and the required procedures and restrictions. Failure to object is not to be considered assent. Exclusion Criteria Subjects will be excluded from the study if any of the following criteria are met at Entry: * Subject was discontinued from SPD485-409 due to a protocol violation, non-compliance, AE, or a serious adverse event (SAE). * Subject has a concurrent chronic or acute illness (such as severe allergic rhinitis or an infectious process requiring antibiotics), disability, or other condition that might confound the results of safety assessments administered in the study or that might increase risk to the subject. Similarly, the subject will be excluded if he or she has any additional condition(s) that in the Investigator's opinion would prohibit the subject from completing the study or would not be in the best interest of the subject. This would include any significant illness or unstable medical condition that could lead to difficulty complying with the protocol. Mild, stable asthma is not exclusionary. * Subject is taking any medication that is excluded. * Female subject who is pregnant or lactating.