Final answer:
Stimulants increase neural activity and alertness, often by enhancing dopamine neurotransmission, resulting in heightened reward and pleasure but with potential for abuse and side effects.
Step-by-step explanation:
Stimulants are a class of drugs that enhance neural activity and raise alertness. Stimulants like amphetamines, including Adderall, cocaine, and caffeine, work by acting as agonists of the dopamine neurotransmitter system, which can lead to their potential for abuse. Amphetamines, a type of stimulants, are particularly known for blocking the reuptake of dopamine, thus increasing its levels in the brain.
Dopamine is a neurotransmitter linked with reward and pleasure, influencing one's desire to keep using the drug. In addition to rewarding effects, stimulants can produce side effects like increased motor activity, reduced appetite, and decreased need for sleep.