Which drugs are known as hallucinogens?

Hallucinogens are substances that significantly alter one's perception, mood, and cognitive processes. The group commonly referred to as psychedelics directly influences the brain's serotonin systems, which in turn can lead to vivid hallucinations, changes in thought processes, and alterations in sensory perception. This category includes well-known substances such as LSD, psilocybin (magic mushrooms), and mescaline.

Psychedelics are specifically known for their ability to create profound changes in the way individuals perceive reality, making them distinctly different from other categories of drugs that do not primarily cause hallucinations or perceptual distortions. Understanding this aspect is crucial when distinguishing between different drug classes. For example, while amphetamines and barbiturates fall under stimulants and depressants, respectively, they do not alter perception in the same way that hallucinogens do. Similarly, analgesics focus on pain relief without affecting sensory perception. Therefore, the correct answer highlights the unique properties of hallucinogens, aligning with how they are explicitly defined in the realm of pharmacology.