This study will assess the safety and tolerability of MTS while attempting to establish the appropriate starting dose for subjects previously on an existing long-acting methylphenidate product.

Attention-Deficit/Hyperactivity Disorder (ADHD) is a psychiatric disorder characterized by 3 main symptoms: inattention, hyperactivity and impulsivity. This study will assess the safety and tolerability of SPD485 while attempting to establish the appropriate starting dose for subjects previously on an existing long-acting methylphenidate product.

Inclusion Criteria:

• Subject must have a primary diagnosis of ADHD
• Subject must be adequately controlled on a stable dose of one of the following medications for a 30 day period: Ritalin LA(r), Concerta(r), or Metadate DC(r), not to exceed 54 mg per day
• Females of childbearing potential must have a negative serum beta Human Chorionic Gonadotropin pregnancy test

Exclusion Criteria:

• A history of mental retardation that would indicate that the subject is not functioning at an age appropriate level intellectually
• A recent history of suspected substance abuse or dependence disorder
• Subject is taking Strattera
• Clinical signs and symptoms of skin irritation or hyper/hypopigmentation at the potential application sites