Final answer:
Stimulants, including synthetic amphetamines and methamphetamine, are psychoactive drugs that increase neural activity, often resulting in euphoria and increased wakefulness but with potential for abuse and adverse effects.
Step-by-step explanation:
Stimulants are a type of psychoactive drug that stimulate the brain, increasing alertness, wakefulness, and often leading to increased speech and motor activity. One of the primary synthetic stimulants created in laboratories is amphetamines, which include compounds like methamphetamine. These synthetic stimulants function by affecting dopamine neurotransmission, leading to feelings of euphoria and pleasure but also have a significant potential for abuse and adverse side effects such as anxiety, hallucinations, and paranoia. Methamphetamine, for example, can be synthesized from precursor chemicals such as pseudoephedrine and has seen a widespread increase in use. Stimulants, both synthetic and naturally occurring, like cocaine and nicotine, have powerful effects on the nervous system, many of which manifest as sympathetic responses—thus, they are sometimes classified as sympathomimetic drugs.