Psychoactive drugA psychoactive drug, psychopharmaceutical, psychoactive agent, or psychotropic drug is a chemical substance that changes the function of the nervous system and results in alterations of perception, mood, cognition, and behavior. These substances may be used medically, recreationally, for spiritual reasons (for example, by altering one's consciousness, as with entheogens for ritual, spiritual, or shamanic purposes), or for research. Some categories of psychoactive drugs may be prescribed by physicians and other healthcare practitioners because of their therapeutic value.
HallucinogenHallucinogens are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mood, and perception as well as other changes. Most hallucinogens can be categorized as either being psychedelics, dissociatives, or deliriants. The word hallucinogen is derived from the word hallucination. The term hallucinate dates back to around 1595–1605, and is derived from the Latin hallūcinātus, the past participle of (h)allūcināri, meaning "to wander in the mind.
DeliriantDeliriants are a subclass of hallucinogen. The term was coined in the early 1980s to distinguish these drugs from psychedelics and dissociatives such as LSD and ketamine, respectively, due to their primary effect of causing delirium, as opposed to the more lucid and less disturbed states produced by other types of hallucinogens. The term generally refers to anticholinergic drugs, which are substances that inhibit the function of the neurotransmitter acetylcholine.
MuscarineMuscarine, L-(+)-muscarine, or muscarin is a natural product found in certain mushrooms, particularly in Inocybe and Clitocybe species, such as the deadly C. dealbata. Mushrooms in the genera Entoloma and Mycena have also been found to contain levels of muscarine which can be dangerous if ingested. Muscarine has been found in harmless trace amounts in Boletus, Hygrocybe, Lactarius and Russula. Trace concentrations of muscarine are also found in Amanita muscaria, though the pharmacologically more relevant compound from this mushroom is the Z-drug-like alkaloid muscimol.
NMDA receptor antagonistNMDA receptor antagonists are a class of drugs that work to antagonize, or inhibit the action of, the N-Methyl-D-aspartate receptor (NMDAR). They are commonly used as anesthetics for animals and humans; the state of anesthesia they induce is referred to as dissociative anesthesia. Several synthetic opioids function additionally as NMDAR-antagonists, such as pethidine, levorphanol, methadone, dextropropoxyphene, tramadol and ketobemidone.
Amanita muscariaAmanita muscaria, commonly known as the fly agaric or fly amanita, is a basidiomycete of the genus Amanita. Native throughout the temperate and boreal regions of the Northern Hemisphere, Amanita muscaria has been unintentionally introduced to many countries in the Southern Hemisphere, generally as a symbiont with pine and birch plantations, and is now a true cosmopolitan species. It associates with various deciduous and coniferous trees.
DepressantDepressants, or central depressants, are drugs that lower neurotransmission levels, or depress or reduce arousal or stimulation in various areas of the brain. Depressants are also colloquially referred to as "downers" as they lower the level of arousal when taken. Depressants do not change the mood or mental state of others. Stimulants, or "uppers," increase mental or physical function, hence the opposite drug class from depressants are stimulants, not antidepressants.
EntheogenEntheogens are psychoactive substances that induce alterations in perception, mood, consciousness, cognition, or behavior for the purposes of engendering spiritual development or otherwise in sacred contexts. The anthropological study has established that entheogens are used for religious, magical, shamanic, or spiritual purposes in many parts of the world.
Psychedelic drugPsychedelics are a subclass of hallucinogenic drugs whose primary effect is to trigger non-ordinary mental states (known as psychedelic experiences or psychedelic "trips") and/or an apparent expansion of consciousness. Sometimes, they are called classic hallucinogens, serotonergic hallucinogens, or serotonergic psychedelics, and the term psychedelic is sometimes used more broadly to include various types of hallucinogens or those which are atypical or adjacent to psychedelia such as salvia and MDMA, respectively; this article uses the narrower definition of psychedelics.
PsychopharmacologyPsychopharmacology (from Greek psȳkhē; pharmakon; and -logia) is the scientific study of the effects drugs have on mood, sensation, thinking, behavior, judgment and evaluation, and memory. It is distinguished from neuropsychopharmacology, which emphasizes the correlation between drug-induced changes in the functioning of cells in the nervous system and changes in consciousness and behavior. The field of psychopharmacology studies a wide range of substances with various types of psychoactive properties, focusing primarily on the chemical interactions with the brain.