Ritalin (methylphenidate hydrochloride) is a prescription central nervous system stimulant used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy. It works by increasing the activity of certain neurotransmitters in the brain, helping improve attention and reduce symptoms of ADHD. Ritalin tablets are available in different strengths, including 5 mg, 10 mg, and 20 mg. Use only as prescribed by a qualified healthcare professional. Ritalin carries important warnings regarding misuse, abuse, addiction, and other adverse effects.