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Hallucinogens are any of a group of substances that alter consciousness; also called psychotomimetic (i.e., mimicking psychosis), mind-expanding, or psychedelic drug. The group includes mescaline, or peyote, which comes from the cactus Lophophora williamsii; psilocin and psilocybin, from the mushrooms Psilocybe mexicana and Stropharia cubensis; and LSD, synthesized from lysergic acid, found in the fungus Claviceps purpurea. 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 amphetamine derivative, were common in the 1980s. Marijuana has hallucinogenic properties but is pharmacologically distinct. Hallucinogens have been used for centuries by certain peoples. The Hindus and the Aztecs 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. Effects 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. Many hallucinogenic drugs share a basic chemical structural unit, the indole ring, which is also found in the nervous system substance serotonin has chemical similarities to both the indole ring and the adrenal hormoneEpinephrine. Clinical research with hallucinogens has resumed after a generation's hiatus. To place these new studies in context, this article reviews the history of hallucinogens' use and abuse, discusses their pharmacological properties, and highlights previous human studies. Research with Iysergic acid diethyl amide and related hallucinogens with thousands of patients and control subjects was associated with acceptable safety when subjects were carefully screened, supervised, and followed up. Data were generated regarding hallucinogens' psychopharmacology, overlap with endogenous psychoses, and psychotherapeutic efficacy. Current American and European studies emphasize systematic psychopharmacology, in addition to psychotherapy protocols. Human hallucinogen research will help define unique mind-brain interfaces, and provide mechanistic hypotheses and treatment options for psychiatric disorders. It is critical that human hallucinogen research in the l990s makes use of state of the art methodologies, or consensually defines when modifications are required. Training and supervisory issues also must be explicitly addressed. Nomenclature Many terms have been used to describe the effects of these drugs, including psychedelic (mind manifesting), psycho-dysleptic (disturbing the mind), phantasticant, psychotogen, oneirogen (producing dreams), entheogen (generating religious experience), phanerothyme (making feelings visible), psychotomimetic, and schizotoxin (Grinspoon and Bakalar, 1979; Stafford, 1992). Psychedelic represents the non-medical, recreational, and illicit use of these drugs, while hallucinogen refers to these compounds within a medical-legal context. The "classical" hallucinogens belong to several chemical families: phenethylamines (e.g., mescaline), indolealklyamines (e.g., psilocybin and N, N-dimethyltryptamine [DMT]), and lysergamides (e.g., LSD and morning glory seeds) (Nichols et al., 1991). 3,4-Methylene-dioxymethamphetamine (MDMA) ("X," "XTC") is a methoxylated amphetamine (phenethylamine), and produces effects that overlap those of classical compounds (Lister et al., 1992). Low doses of the dissociative anesthetics, phencyclidine and ketamine (Siegel, 1978), and antimuscarinic agents (Ketchum et al., 1973) also share subjective properties with the hallucinogens. However, hallucinogens do not produce anesthesia at high doses, as do the former compounds, nor is there a clouding of consciousness at "psychedelic" doses, as with the latter. A clinically useful manner of representing hallucinogens refers to their temporal properties: onset, peak effect, and duration of action. An "ultra-short-acting" drug's onset is less than 1 minute, peak effects occur within 5 minutes, and duration is 30 minutes or less. Intravenous DMT is an example (Strassman et al., 1994). A "short-acting" hallucinogen's onset is between 5 and 15 minutes, peak effects are within 15 to 60 minutes, and duration is 1 to 2 hours (e.g., intramuscular N, N-diethyltryptamine; Faillace et al., 1967). "Intermediate-acting" hallucinogens include the orally active tryptamine psilocybin (Rinkel et al., 1960). Onset is within 15 to 30 minutes; peak effects are at 1 to 3 hours, with duration up to 6 hours. "Long-acting" hallucinogens include oral LSD and mescaline (Hoch et al., 1952), with onset at 30 to 90 minutes, peak effects at 3 to 5 hours, and duration of 8 to 12 hours. "Ultra-long-acting" compounds include the poorly characterized African plant drug ibogaine (Fernandez, 1982). Duration of action may last 18 to 24 hours. Prevalence of Use Hallucinogen use in the United States remained relatively constant from the late 1960s to the late 1980s (Pope et al., 1990). However, data from the National Institute on Drug Abuse (NIDA) show an increase in any LSD use by high school seniors "within the last 12 months" from 4.8% to 5.6% from 1988 to 1992. While the magnitude of this rise is slight, it stands in contrast to the abuse of other drugs. For example, the proportion of seniors who had used any cocaine dropped from 7.9% to 3.1% during the same period (Johnston et al., 1993). Thus, the proportion of respondents who reported any use of LSD was almost twice as high as the proportion reporting any cocaine use by high school seniors in 1992. The 1990 NIDA statistics reveal that lifetime prevalence rates for hallucinogens were about the same as those for cocaine, and 7 to 8 times higher than for heroin. LSD ranked first in the categories of "most intense" and "longest" high among respondents. Between 13 and 17 million individuals in this country have used a hallucinogen at least once (NIDA, 1991). Legal Status Hallucinogens reside in Schedule 1 of the Controlled Substances Act of 1970, which is reserved for drugs with "high abuse potential," "lack of established safety even under medical supervision," and "no known use in medical treatment" (Anonymous, 1970).
Approximate Word count = 4169
Approximate Pages = 16.7
(250 words per page double spaced)
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