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hallucinogenic drug(həlo͞o'sənōjĕn`ĭk), any of a group of substances that alter consciousness; also called psychotomimetic (i.e., mimicking psychosispsychosis
, in psychiatry, a broad category of mental disorder encompassing the most serious emotional disturbances, often rendering the individual incapable of staying in contact with reality.
..... Click the link for more information. ), mind-expanding, or psychedelic drug. The group includes mescaline, or peyotepeyote
, spineless cactus (Lophophora williamsii), ingested by indigenous people in Mexico and the United States to produce visions. The plant is native to the SW United States, particularly S Texas, and Mexico, where it grows in dry soil.
..... Click the link for more information. , which comes from the cactus Lophophora williamsii; psilocin and psilocybin, from the mushrooms Psilocybe mexicana and Psilocybe cubensis; and LSDLSD
or lysergic acid diethylamide
, alkaloid synthesized from lysergic acid, which is found in the fungus ergot (Claviceps purpurea). It is a hallucinogenic drug that intensifies sense perceptions and produces hallucinations, mood changes, and changes in the
..... Click the link for more information. , synthesized from lysergic acid, found in the fungus Claviceps purpurea (see ergotergot
, disease of rye and other cereals caused by the fungus Claviceps purpurea. The cottony, matlike body, or mycelium, of the fungus develops in the ovaries of the host plant; it eventually turns into a hard pink or purple body, the sclerotium, or ergot, that resembles
..... Click the link for more information. ). These alkaloids have also been produced synthetically. Newer hallucinogens, such as PCP (phencyclidine, or "angel dust"), a drug originally used as an anesthetic, and MDMA ("Ecstasy"), an amphetamineamphetamine
, any one of a group of drugs that are powerful central nervous system stimulants. Amphetamines have stimulating effects opposite to the effects of depressants such as alcohol, narcotics, and barbiturates.
..... Click the link for more information. derivative, were common in the 1980s. Marijuanamarijuana
drug obtained from the flowering tops, stems, and leaves of the hemp plant, Cannabis sativa (see hemp) or C. indica; the latter species can withstand colder climates.
..... Click the link for more information. has hallucinogenic properties but is pharmacologically distinct.
Hallucinogens have been used for centuries by certain peoples. The Hindus and the AztecsAztec
, Indian people dominating central Mexico at the time of the Spanish conquest. Their language belonged to the Nahuatlan subfamily of Uto-Aztecan languages. They arrived in the Valley of Mexico from the north toward the end of the 12th cent.
..... Click the link for more information. used them to facilitate meditation, cure illness, and enhance mystical powers. Many North American tribal peoples still use hallucinogenic mushrooms and peyote in tribal rituals. During the 1950s and 60s a number of hallucinogenic drugs were investigated in studies, but such drugs were largely discredited by association with the so-called drug culture that developed in the 1960s. Under the Controlled Substances Act (1970) they have been classified as having a high potential for abuse, having no accepted medical use in treatment, and not having accepted safety for use under medical supervision. In the 21st cent., however, there has been some experimental investigation into the potential use of psilocybin and, to a lesser degree, LSD in the treatment of anxiety and stress in terminally ill patients and of addiction.
Hallucinogens produce a wide range of effects, depending on the properties, dosage, and potency of the drug, the personality and mood of the drug taker, and the immediate environment. Visually, perception of light and space is altered, and colors and detail take on increased significance. If the eyes are closed the drug taker often sees intense visions of different kinds. Nonexistent conversations, music, odors, tastes, and other sensations are also perceived. The sensations are often either very pleasant or very distasteful and disturbing. The drugs frequently alter the sense of time and cause feelings of emptiness. For many individuals the separation between self and environment disappears, leading to a sense of oneness or holiness.
The effects, sometimes referred to as a "trip," can last from an hour to a few days. "Bad trips," full of frightening images, monsters, and paranoid thoughts are known to have resulted in accidents and suicides. Flashbacks (unexpected reappearances of the effects) can occur months later.
Physiologically, the drugs act as mild stimulants of the sympathetic nervous system, causing dilation of the pupils, constriction of some arteries, a rise in blood pressure, and increased excitability of certain spinal reflexes. Psilocybin has been shown to produce decreased blood flow and activity in the thalamus and other brain areas that connect different parts of the brains. Many hallucinogenic drugs share a basic chemical structural unit, the indole ring, which is also found in the nervous system substance serotoninserotonin
, organic compound that was first recognized as a powerful vasoconstrictor occurring in blood serum. It was partially purified, crystallized, and named in 1948, and its structure was deduced a year later.
..... Click the link for more information. . Mescaline has chemical similarities to both the indole ring and the adrenal hormone epinephrineepinephrine
, hormone important to the body's metabolism, also known as adrenaline. Epinephrine, a catecholamine, together with norepinephrine, is secreted principally by the medulla of the adrenal gland.
..... Click the link for more information. .
See publications of the Drugs & Crime Data Center and Clearinghouse, the Bureau of Justice Statistics Clearinghouse, and the National Clearinghouse for Alcohol and Drug Information.