(Virgilio Marin) The Centers for Disease Control and Prevention estimates that around 62 percent of children with attention-deficit hyperactivity disorder (ADHD) are taking medications for the disease. One of the most common prescription drugs for ADHD is methylphenidate. The drug, commonly known as Ritalin, is a central nervous system stimulant linked to numerous side effects, including anxiety, nausea, difficulty sleeping, vision problems, increase in blood pressure and loss of appetite.