Hallucinogens and Related Disorders

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Editor: Kristin Key
Date: 2012
Publisher: Gale, a Cengage Company
Document Type: Topic overview
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Hallucinogens and Related Disorders


Hallucinogens are a chemically diverse group of drugs that cause changes in a person's thought processes, perceptions of the physical world, and sense of time passing. They can be found naturally in some plants and can be synthesized in the laboratory. Most hallucinogens are abused as recreational drugs. Hallucinogens are also called psychedelic drugs.


Hallucinogen use, excluding MDMA, peaked in the United States in the late 1960s as part of the counterculture movement. It then gradually declined until the early 1990s, when it increased. The 2010 U.S. National Survey on Drug Use and Health reported 1.2 million persons had used hallucinogens in the past month, with 695,000 persons taking MDMA, or ecstasy.


Use of hallucinogens is at least as old as civilization. Many cultures have recorded eating certain plants specifically to induce visions or alter the perception of reality. These hallucinations were often part of a religious

Number of emergency department visits involving ecstasy, 2004-2008.

Number of emergency department visits involving ecstasy, 2004-2008. Substance Abuse and Mental Health Services Administration, Center for Behavioral Health Statistics and Quality, “Emergency Department Visits Involving Ecstasy,” The DAWN Report (March 24, 2011).

Available online at http://oas.samhsa.gov/2k11/DAWN027/Ecstasy.htm . (Graph by PreMediaGlobal. © 2012 Cengage Learning.)

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or prophetic experience. Shamans in Siberia were known to eat the hallucinogenic mushroom Amanita muscaria. The ancient Greeks and the Vikings also used naturally occurring plant hallucinogens. Peyote, a spineless cactus native to the southwestern United States and Mexico, was used by native peoples, including the Aztecs, to produce visions.

Although several hundred plants are known to contain compounds that cause hallucinations, most hallucinogens are synthesized in illegal laboratories for delivery as street drugs. The best known hallucinogens are lysergic acid diethylamide (LSD), mescaline, psilocybin, and MDMA (ecstasy). Phencyclidine (PCP, angel dust) can produce hallucinations, as can amphetamines and marijuana, but these drugs are considered dissociative drugs, rather than hallucinogens, and act by a different pathway from classic hallucinogens. Dextromorphan, the main ingredient in many cough medicines, has become popular among some populations because of the PCP-like hallucinations it produces. In addition, new designer drugs that are chemical variants of classic hallucinogens are apt to appear on the street at any time. One drug that only recently was added to Schedule I of the 1970 Controlled Substances Act (the classification for many other “hard” drugs with no known therapeutic value) is 5-methoxy-N, N-diisopropyltryptamine (5-MeO-DIPT), a drug derived from the chemical tryptamine that is more commonly known as “Foxy” or “Foxy Methoxy.” A related hallucinogen, dimethyltryptamine, occurs naturally in plants in the Amazon but is now synthesized in labs. This drug, more commonly known as DMT, can be a powerful hallucinogen.

Although the various hallucinogens produce similar physical and psychological effects, they are a diverse group of compounds. However, all hallucinogens appear to affect the brain in similar ways. While the mechanism of action of hallucinogens is not completely understood, researchers have shown that these drugs bind with one type of serotonin receptor (5-HT2) in the brain.

Serotonin is a neurotransmitter that facilitates transmission of nerve impulses in the brain and is associated with feelings of well-being, as well as many physiological responses. When a hallucinogenic compound binds with serotonin receptors, serotonin is blocked from those receptor sites, and nerve transmission is altered. There is an increase in free (unbound) serotonin in the brain. The result is a distortion of the senses of sight, sound, and touch, disorientation in time and space, and alterations of mood. In the case of hallucinogen intoxication, however, a person is not normally delirious, unconscious, or dissociated. He or she is aware that these changes in perception are caused by the hallucinogen.

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LSD was first synthesized by Albert Hoffman for a pharmaceutical company in Germany in 1938 while he was searching for a headache remedy. Hoffman discovered the hallucinogenic properties of LSD accidentally in 1943. The drug became popular with the counterculture youth of the mid-1960s when its sense-altering properties were reputed to offer a window into enhanced creativity and self-awareness. LSD also occurs naturally in morning glory seeds.

Pure LSD is a white, odorless, crystalline powder that dissolves easily in water, although contaminants can cause it to range in color from yellow to dark brown. LSD was listed as a Schedule I drug under the Controlled Substance Act of 1970, meaning that it has no medical or legal uses and has a high potential for abuse. LSD is not easy to manufacture in a home laboratory, and some of its ingredients are controlled substances that are difficult to obtain. However, LSD is very potent, and a small amount can produce a large number of doses.

On the street, LSD is sold in several forms. Microdots are tiny pills smaller than a pinhead. Windowpane is liquid LSD applied to thin squares of gelatin. Liquid LSD can also be sprayed on sugar cubes. The most common street form of the drug is liquid LSD sprayed onto blotter paper and dried. The paper, often printed with colorful or psychedelic pictures, is divided into tiny squares, each square being one dose. Liquid LSD can also be sprayed on the back of a postage stamp and licked off. Street names for the drug include “acid,” “yellow sunshine,” “windowpane,” “cid,” “doses,” “trips,” and “boomers.”


Mescaline is a naturally occurring plant hallucinogen. Its primary source is the cactus Lophophora williamsii. This cactus is native to the southwestern United States and Mexico. The light blue-green plant is spineless and has a crown called a “peyote button.” This button contains mescaline and can be eaten or made into a bitter tea. Mescaline is also the active ingredient of at least ten other cacti of the genus Trichocereus that are native to parts of South America.

Mescaline was first isolated in 1897 by the German chemist Arthur Heffter and first synthesized in the laboratory in 1919. Some experiments were done with the drug to determine whether it was medically useful, but no medical uses were found. However, peyote is culturally significant. It has been used for centuries as part of religious celebrations and vision quests of Native Americans. The Native American Church, which fuses elements of Christianity with indigenous practices, has long used peyote as part of its religious practices.

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In 1970, mescaline was listed as a Schedule I drug under the Controlled Substances Act. However, that same year, the state of Texas legalized peyote for use in Native American religious ceremonies. In 1995, a federal law was passed making peyote legal (but only for this use) in all 50 states.


Psilocybin is the active ingredient in what are known on the street as “magic mushrooms,” “shrooms,” “mushies,” or “Mexican mushrooms.” There are several species of mushrooms that contain psilocybin, including Psilocybe mexicana, P. muscorumi, and Stropharia cubensis. These mushrooms grow in most moderate, moist climates.

Psilocybin-containing mushrooms are usually cooked and eaten (they have a bitter taste) or dried and boiled to make a tea. Although psilocybin can be made synthetically in the laboratory, there is no street market for synthetic psilocybin, and virtually all the drug comes from cultivated mushrooms. In the United States, it is legal to possess psilocybin-containing mushrooms, but it is illegal to traffic in them, and psilocybin and psilocyn (another psychoactive drug found in small quantities in these mushrooms) are both Schedule I drugs.


MDMA, short for 3,4-methylenedioxymethamphe-tamine, and better known as “ecstasy,” “XTC,” “E,” “X,” or “Adam,” has become an increasingly popular club drug since the 1980s. The hallucinogenically active portion of the drug is chemically similar to mescaline, while its stimulant portion is similar to methamphetamine. MDMA was first synthesized in 1912 by a German pharmaceutical company looking for a new compound that would stop bleeding. The company patented the drug but never did anything with it. A closely related drug, methylenedioxyamphetimine, or MDA, was tested by a pharmaceutical company as an appetite suppressant in the 1950s, but its use was discontinued when it was discovered to have hallucinogenic properties. In the 1960s, MDA was a popular drug of abuse in some large cities such as San Francisco.

During the early 1980s, therapists experimented with MDMA, which was legal at the time, as a way to help patients open up and become more empathetic. Recreational use soon followed, and it was declared an illegal Schedule I drug in 1985. For about a year between 1987 and 1988, the drug was again legal as the result of court challenges, but it permanently joined other Schedule I hallucinogens in March 1988.

MDMA is a popular club drug often associated with all-night raves or dance parties. The drug, sold in tablets, is attractive because it combines stimulant effects that allow ravers to dance for hours with a feeling of empathy, reduced anxiety, reduced inhibitions, and euphoria. Some authorities consider MDA and MDMA to be stimulant-hallucinogens and do not group them with classic hallucinogens such as LSD, but research indicates that MDA and MDMA affect the brain in the same way as classic hallucinogens. The American Psychiatric Association considers MDMA to be a drug that can cause hallucinogen-related disorders.


PMMA (para-Methoxymethamphetamine) is a hallucinogen with effects similar to MDMA, causing rapid heartbeat, high blood pressure, seizures, kidney failure, hyperthermia, hallucinations, and death. The compound in PMMA is often found in MDMA, making the substance even more potent and potentially fatal.


Salvia (Salvia divinorum) is known by many other names, including “Sally D,” “Magic Mint,” “Shepherdess Herb,” “Ska Maria Pastora,” “Diviners Sage,” and “Sage of the Seers.” Originating in Mexico, the drug is a perennial herb in the mint family. It grows in clusters up to three feet high with green leaves and white and purple flowers. Salvia is a potent psychoactive drug containing a chemical called salvinorin A, causing hallucinations noted to be up to five times more potent than the drug LSD. It is thought to act on opioid receptors of the brain, causing both physical and visual impairment and hallucinogenic effects. It is sold in the form of leaves, seeds, and extract and can be chewed or smoked when used. Salvia is not regulated by the federal government, but many states are creating legislation to ban the cultivation and sale of this plant.

Some hallucinogens (such as Salvia), act on opioid receptors of the brain, which like many narcotics, affect perceived levels of physical pain. As such, their use in the future may be implicated as therapeutic agents in pain control. Research and attention to legislation regarding intent for this use are ongoing.

Jimson weed

Jimson weed (Datura stramonium) is an herb producing fragrant flowers with a trumpet–like appearance. It grows as a bush in warm climates, and the seeds and leaves of the plant are poisonous and potentially fatal. Also known as “Devils Trumpet,” “Devils Weed,” “Moonflower,” “Thorn Apple,” and “Locoweed,” jimson weed induces hallucinations, and users are often unaware of its toxicity. Effects include delirium, hallucinations, amnesia, and violent behavior; symptoms of overdose include seizure, coma, and respiratory arrest. Ingestion of

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the plant requires emergency treatment and hospitalization, as symptoms may last for up to three days.

Causes and symptoms

Hallucinogens are attractive to recreational drug users for a number of reasons:

  • They are minimally addictive and there are no physical withdrawal symptoms upon stopping use.
  • They produce few serious or debilitating physical side effects.
  • They do not usually produce a delusional state, excessive stupor, or excessive stimulation.
  • They are easily and cheaply available.
  • They produce a high that gives the illusion of increasing creativity, empathy, or self-awareness.
  • Deaths from overdoses are rare.

Despite their perceived harmlessness, strong hallucinogens such as LSD can cause frightening and anxiety-evoking emotional experiences, known as “bad trips.” Flashbacks, where the sensations experienced while under the influence of a drug recur uncontrollably without drug use, can occur for months after a single drug use. During hallucinogen intoxication, reality may be so altered that a person may endanger himself by believing he is capable of feats such as flying off buildings. Hallucinogens also may induce or cause a worsening of latent psychiatric disorders such as anxiety, depression, and psychosis. Hallucinogens can also cause paranoia, long-term memory loss, personality changes (especially if there is a latent psychiatric disorder), and psychological drug dependence.

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Psychological symptoms

Hallucinogens work primarily on the perception of reality. They usually do not create true hallucinations, which are imagined visions or sounds (voices heard in the head, for example) in the absence of any corresponding reality. Instead, classic hallucinogens alter the perception of something that is physically present. A face may appear to “melt” or colors may become brighter, move, and change shape. Sounds may be “seen,” rather than heard.

More than with other drugs, the mental state of the hallucinogen user and the environment in which the drug is taken influence the user's experience. LSD, especially, is known for symptoms that range from mellowness and psychedelic visions (“good trips”) to anxiety and panic attacks (“bad trips”). Previous good experiences with a drug do not guarantee continued good experiences. People with a history of psychiatric disorders are more likely to experience harmful reactions, as are those who are given the drug without their knowledge.

Normally, mescaline and psilocybin produce uniformly milder symptoms than LSD. During a single drug experience, the user can experience a range of symptoms. Mood can shift from happy to sad or pleasant to frightening and back again several times. Some symptoms occur primarily with MDMA, as indicated. Psychological symptoms of hallucinogen intoxication include:

  • distortion of sight, sound, and touch
  • confusion of the senses—sounds are “seen” or vision is “heard”
  • disorientation in time and space
  • delusions of physical invulnerability (especially with LSD)
  • paranoia
  • unreliable judgment and increased risk taking
  • anxiety attacks
  • flashbacks after the drug has been cleared from the body
  • blissful calm or mellowness
  • reduced inhibitions
  • increased empathy (MDMA)
  • elation or euphoria
  • impaired concentration and motivation
  • long-term memory loss
  • personality changes, especially if there is a latent psychiatric disorder
  • psychological drug dependence

Physical symptoms

Although the primary effects of hallucinogens are on perceptions, some physical effects do occur. Physical symptoms include:

  • increased blood pressure
  • increased heart rate
  • nausea and vomiting (especially with psilocybin and mescaline)
  • blurred vision, which can last after the drug has worn off
  • poor coordination
  • enlarged pupils
  • sweating
  • diarrhea (plant hallucinogens)
  • restlessness
  • muscle cramping (especially clenched jaws with MDMA)
  • dehydration (MDMA)
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—Can be experienced as a troubled feeling, a sense of dread, fear of the future, or distress over a possible threat to a person's physical or mental well-being.
—A mental state characterized by feelings of sadness, despair, and discouragement.
—Best known of the so-called designer amphetamines, also known as MDMA. It produces both stimulant and hallucinogenic effects.
—To hear, see, or otherwise sense things that are not real. Hallucinations can result from nervous system abnormalities, mental disorders, or the use of certain drugs.
—The most common illegally produced amphetamine.
Panic attack
—A period of intense fear or discomfort with a feeling of doom and a desire to escape. The person may shake, sweat, be short of breath, and experience chest pain.
—A widely distributed neurotransmitter that is found in blood platelets, the lining of the digestive tract, and the brain, and that works in combination with norepinephrine. It causes very powerful contractions of smooth muscle, and is associated with mood, attention, emotions, and sleep. Low levels of serotonin are associated with depression. Large amounts of serotonin are released after ingestion of MDMA.
  • serious increase in body temperature, leading to seizures (MDMA)


Although not all experts agree, the diagnosis of mental disorders recognizes two hallucinogen-related disorders: hallucinogen dependence and hallucinogen abuse. Hallucinogen dependence is the continued use of hallucinogens even when the substances cause the affected individual significant problems, or when the individual knows of adverse effects (memory impairment while intoxicated, anxiety attacks, flashbacks) but continues to use the substances anyway. “Craving” hallucinogens after not using them for a period of time has been reported. Hallucinogen abuse is repeated use of hallucinogens even after they have caused the user impairment that undermines his or her ability to fulfill obligations at work, school, or home, but the use is usually not as frequent as it is among dependent users. In addition to these two disorders, the American Psychiatric Association recognizes eight hallucinogen-induced disorders. These are:

  • hallucinogen intoxication
  • hallucinogen persistent perception disorder (flashbacks)
  • hallucinogen intoxication delirium
  • hallucinogen-induced psychotic disorder with delusions
  • hallucinogen-induced psychotic disorder with hallucinations
  • hallucinogen-induced mood disorder
  • hallucinogen-induced anxiety disorder
  • hallucinogen-related disorder not otherwise specified

Hallucinogen dependence and abuse are normally diagnosed from reports by the patient (or person accompanying the patient) of use of a hallucinogenic drug. Active hallucinations and accompanying physical symptoms can confirm the diagnosis but need not be present. Routine drug screening does not detect LSD in the blood or urine, although specialized laboratory methods can detect the drug. Hallucinogen dependence differs from other drug dependence in that there are no withdrawal symptoms when the drug is stopped, and the extent of tolerance (needing a higher and higher dose to achieve the same effect) appears minimal.

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, also known as the DSM-5, is due for publication in May 2013. This edition may include proposed changes and revisions to some current diagnostic criteria for psychiatric diagnoses, including combining “Hallucinogen Abuse” and “Hallucinogen Dependence” into the single diagnosis of “Hallucinogen Use Disorder.”

Hallucinogen intoxication is diagnosed based on psychological changes, perceptual changes, and physical symptoms that are typical of hallucinogen use. These changes must not be caused by a general medical condition, other substance abuse, or another mental disorder.

Hallucinogen persisting perception disorder, better known as “flashbacks,” occur after hallucinogen use followed by a period of lucidity. Flashbacks may occur weeks or months after the drug was used and may occur after a single use or many uses.

To be diagnosed as a psychiatric disorder, flashbacks must cause significant distress or interfere with daily life activities. They can come on suddenly with no

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warning or be triggered by specific environments. Flashbacks may include emotional symptoms, seeing colors, geometric forms, or, most commonly, persistence of trails of light across the visual field. They may last for months. Flashbacks are most strongly associated with LSD.

Hallucinogen intoxication delirium is rare unless the hallucinogen is contaminated by another drug or chemical such as strychnine. In hallucinogen intoxication, the patient is still grounded in reality and recognizes that the experiences of altered perception are due to using a hallucinogen. In hallucinogen intoxication delirium, the patient is no longer grounded in reality. Hallucinogen-induced psychotic disorders are similar in that the patient loses touch with reality. Psychotic states can occur immediately after using the drug, or days or months later.

Hallucinogen-induced mood disorder and hallucinogen-induced anxiety disorder are somewhat controversial, as hallucinogen use may uncover latent or pre-existing anxiety or mood disorders rather than being the cause of them. However, it does appear that MDMA use can cause major depression.


Acute treatment is aimed at preventing the patient from harming himself or anyone else. Since most people experiencing hallucinogen intoxication remain in touch with reality, “talking down” or offering reassurance and support that emphasizes that the disturbing sensations, anxiety, panic attack, or paranoia will pass as the drug wears off is often helpful. Patients are kept in a calm, pleasant, but lighted environment and are encouraged to move around while being helped to remain oriented to reality. Occasionally, drugs such as lorazepam are given for anxiety. Complications in treatment occur when the hallucinogen has been contaminated with other street drugs or chemicals. The greatest life-threatening risk is associated with MDMA, in which users may develop dangerously high body temperatures. Reducing the patient's temperature is an essential acute treatment.

Treatment for long-term effects of hallucinogen use involves long-term psychotherapy after drug use has stopped. Many people find 12-step programs or group support helpful. In addition, underlying psychiatric disorders must be addressed.


Because hallucinogens are not physically addictive, many people are able to stop using these drugs successfully.

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  • What risks are associated with hallucinogen use?
  • What symptoms are associated with hallucinogen dependence?
  • Does having hallucinogen dependence and abuse put me at risk for other health conditions?
  • Can you recommend any treatment and support groups for me?

However, users may be haunted by chronic problems such as flashbacks or mood and anxiety disorders either brought about or worsened by use of hallucinogens. It is difficult to predict who will have long-term complications and who will not.


Hallucinogen use is difficult to prevent, because these drugs have a false reputation for being nonaddictive and harmless. Drug education and social outlets that provide people with a sense of self-worth are the best ways to prevent hallucinogen and other substance abuse.



American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text rev. Washing-ton, DC: American Psychiatric Association, 2000.

American Psychological Association. Publication Manual of the American Psychological Association, 6th ed. Washington, DC: American Psychological Association, 2009.

Erickson, Carlton K, Ph.D. Addiction Essentials: The Go-To Guide for Clinicians and Patients. New York, NY: W. W. Norton … Company, 2011.

Galanter, Marc, and Herbert D. Kleber, eds. Textbook of Substance Abuse Treatment, 2nd ed. Washington, DC: American Psychiatric Press, Inc., 2008.

Holland, Julie, ed. Ecstasy: The Complete Guide. Kindle edition. Rochester, Vermont: Park Street Press, 2010.

North, Carol, and Sean Yutzy. Goodwin and Guze's Psychiatric Diagnosis. New York, NY: Oxford University Press, 2010.

Sadock, Benjamin J., Virginia Alcott Sadock, and Pedro Ruiz, eds. Kaplan and Sadock's Comprehensive Textbook of Psychiatry, 2nd ed. New York, NY: Lippincott Williams … Wilkins, 2009.

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National Institute on Drug Abuse. “NIDA InfoFacts: Hallucinogens—LSD, Peyote, Psilocybin, and PCP.” http://drugabuse.gov/infofacts/hallucinogens.html (accessed November 14, 2011).

U.S. Drug Enforcement Administration. “Hallucinogens.” http://www.justice.gov/dea/concern/hallucinogens.html (accessed November 14, 2011).


American Psychological Association, 750 First Street NE, Washington, DC, 20003, (202) 336-5500, http://www.apa.org/index.aspx .

National Institute on Drug Abuse, 6001 Executive Blvd., Rm. 5213, Bethesda, MD, 20892, (301) 442-1124; Spanish: (240) 221-4007, information@nida.nih.gov, http://www.nida.nih.gov .

The Partnership at Drugfree.org , 352 Park Ave. South, 9th Fl., New York, NY, 10010, (212) 922-1560, http://www.drugfree.org .

Substance Abuse and Mental Health Services Administration, 1 Choke Cherry Rd., Rockville, MD, 20857, (877) SAMHSA-7 (726-4727), (800) TTY: 487-4889, Fax: (240) 221-4292, SAMHSAInfo@samhsa.hhs.gov, http://www.samhsa.gov .

Tish Davidson, A.M.
Emily Jane Willingham, Ph.D.
Laura Jean Cataldo, RN, Ed.D.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

Source Citation

Source Citation   (MLA 8th Edition)
Davidson, Tish, et al. "Hallucinogens and Related Disorders." The Gale Encyclopedia of Mental Health, edited by Kristin Key, 3rd ed., vol. 1, Gale, 2012, pp. 732-738. Gale Health and Wellness, https%3A%2F%2Flink.gale.com%2Fapps%2Fdoc%2FCX4013200220%2FHWRC%3Fu%3Dmnkanokahs%26sid%3DHWRC%26xid%3Dd5e4c359. Accessed 13 Dec. 2019.

Gale Document Number: GALE|CX4013200220