Dexmethylphenidate is used as part of a treatment program to control symptoms of attention deficit hyperactivity disorder (ADHD; more difficulty focusing, controlling actions, and remaining still or quiet than other people who are the same age) in adults and children. Dexmethylphenidate is in a class of medications called central nervous system (CNS) stimulants. It works by increasing the amounts of certain natural substances in the brain.