Final answer:
CNS stimulants are used to treat ADHD, narcolepsy, and sometimes obesity by increasing alertness and stimulating the brain. Amphetamines, a common type of these stimulants, work by enhancing dopamine activity, though they also have the potential for abuse.
Step-by-step explanation:
CNS stimulants are a class of drugs that are primarily used to increase alertness, attention, and energy by stimulating the brain and nervous system. These stimulants, which include amphetamines and modafinil, are commonly prescribed to treat conditions such as attention deficit hyperactivity disorder (ADHD), narcolepsy, and occasionally obesity. Amphetamines, for example, function by blocking the reuptake of dopamine, thus enhancing the neurotransmitter's activity, which can improve impulse control in people with ADHD. Despite their therapeutic uses, CNS stimulants also carry a risk for abuse due to their potential to increase dopamine neurotransmission, which is associated with reward and craving.