hallucinogen
n. a substance capable of producing a sensory effect (visual, auditory, olfactory, gustatory, or tactile) in the absence of an actual stimulus. Because they produce alterations in perception, cognition, and mood, hallucinogens are also called psychedelic drugs or psychedelics (from the Greek, meaning “mind-manifesting”). They are a group of heterogeneous compounds, many of which are naturally occurring; others are produced synthetically. Many hallucinogens are structurally similar to one of several neurotransmitters, which may be used as a mechanism of categorization. For example, serotonin-like hallucinogens include the indolealkylamines, exemplified by lysergic acid diethylamide (see LSD), psilocin, DMT, DET, and bufotenin; catecholamine-like hallucinogens include the phenylethylamines and their derivatives, such as mescaline, DOM, MDA, and
MDMA. Both classes in general produce visual hallucinations via activity on subtypes of serotonin receptors. Other hallucinogens include PCP and various natural substances, including ayahuasca. —hallucinogenic
adj.