Substance Index

Hallucinogens are a class of psychoactive substances that produce strong changes in perception, mood, and thought. The experience often feels like a different state of consciousness, not a stronger or weaker version of normal awareness. There are three subclasses of hallucinogens: psychedelics, dissociatives, and deliriants. Each subclass acts on a different brain system and produces a different type of experience. The name comes from the Latin hallucinari, which means "to wander in the mind."