Ritalin is a central nervous system stimulant. Methylphenidate affects chemicals in the brain and nerves that contribute to hyperactivity and impulse control.Ritalin is used to treat attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD), and narcolepsy. it is one molecue away from being crack cocaine but yet black children are given this drug so they canlearn in school while their fathers are locked up for selling cocaine.