This chapter discusses some of the current thinking about hyperactivity and Ritalin. Ritalin is often prescribed to soothe the parents' anxieties, conflicts, and exasperation at particular times of their life, irrespective of the accuracy of the diagnosis, the needs of their children, the long-term side effects of the drug, or the possibility of the child benefiting from psychological therapies. Ritalin, the psychostimulant drug methylphenidate, belongs to the amphetamine group. In adults, it acts as a psychostimulant and causes severe addiction while, for unknown reasons, it has a sedative effect in children. The speed at which the diagnosis of attention deficit hyperactivity disorder (ADHD) is made and the diffusion of Ritalin to treat it, is a worrying trend, particularly while there is still a lack of knowledge about both the diagnosis of ADHD and the side effects of Ritalin.