central nervous system stimulant (SEN-trul NER-vus SIS-tum STIM-
yoo-lunt) A type of drug that increases the levels of certain
chemicals in the brain and increases alertness, attention,
energy, and physical activity. Central nervous system stimulants
also raise blood pressure and increase heart rate and breathing
rate. They are used to treat depression, attention deficit
hyperactivity disorder (a disorder in which a person has
problems paying attention, controlling actions, and remaining
still or quiet), and narcolepsy (a sleep disorder). Also called
CNS stimulant.