Hallucinogen Sources
Plant sources.
LSD, or lysergic acid diethylamide, the prototypical and most potent natural hallucinogen, is extracted from fungal rye. Related hallucinogens are mescaline from peyote cacti, psilocybin and psilocin from mushrooms, and ibogaine from the shrub Tabernanthe. All plant hallucinogens have serotonin-like chemical structures.
Synthetic sources. Of the synthesized hallucinogens, PCP (phencyclidine) and ketamine are key examples. PCP was developed in the 1950s and used through 1965 as an anesthetic, and ketamine was designed as a less potent veterinary anesthetic. Both of these drugs and dextromethorphan induce glutamate-related hallucinations.
Newer designer drugs, including the tryptamines, methylenedioxymethamphetamine (MDMA, or ecstasy), the herbal Salvia divinorum , and numerous amphetamine-like drugs, are not specifically members of the hallucinogen drug class. However, they can exert hallucinogenic effects through non-serotonin or non-glutamate pathways.
Immediate Effects
Hallucinogens distort perceptions of self, emotion, sensations, and moods; they also impair judgment and cause dissociation. Depersonalization, or a disconnection from the physical body and surroundings, and dissociation, or a separation of the mind from the physical self and environment, can lead users to lose control of their body and actions. Each drug experience, or trip, causes unpredictable hallucinations according to the user’s environment, the user’s emotional state of mind, and the timing, type, and amount of drug used.
LSD, mescaline, psilocybin, and ibogaine affect serotonin (5HT) actions at the 5HT-2 receptors in the cerebral cortex and locus cerebellum to impair control of mood, senses, hunger, and body temperature. The onset of effect is thirty to ninety minutes; LSD and mescaline trips can last up to twelve hours, but psilocybin trips are often only four to six hours. Serotonin blockade results in rapid psychologic fluctuations of fear to euphoria; bizarre but peaceful delusions of enhanced abilities are as likely as time alterations and loss of control that cause panic and terror. Sensory experiences of plant hallucinogens become uniquely confused and overlap. This crossover, called synesthesia, is common and causes an intense and unusual ability to see sounds, to hear or feel colors, and to taste sights.
Unlike these sensory delusions, PCP and ketamine induce primarily dissociative effects by N-methyl-D-aspartic acid antagonism at glutamate brain receptors to cause bizarre distortions of reality. Glutamate blockade results in feelings of power, impaired memory, numbness to pain, detachment from the body and bodily responses, and altered senses. As with plant hallucinogens, out-of-body sensations may be pleasantly empowering or terrifying. Ketamine and PCP both cause an immediate dopamine-related rush of euphoria, followed by anxiety and emotional lability after the dopamine peak. Although PCP is more potent and longer-lasting than ketamine, both drugs are delivered straight to the brain when smoked or snorted, so they take effect within minutes.
PCP-like hallucinogens are known for their quicker onset, shorter duration, and reduced potency compared with plant hallucinogens. For example, dimethyltryptamine
(DMT), a designer drug with hallucinatory properties, takes action within two to five minutes, but the effects last only twenty to sixty minutes. Of the PCP-like hallucinogens, dextromethorphan
(DXM) alone has specific dose-effect plateaus. Two ounces of 3 milligrams (mg) per milliliter of DXM cough medicine causes mild sensory changes, and complete dissociation occurs at 10 ounces or greater. DXM effects can last for six hours after use and are particularly dangerous because of overdose risk with combination products.
Hallucinogens cause physiologic changes in part through sympathetic nervous system activation. Immediate effects include increased heart rate and blood pressure, sweating and flushing, increased body temperature, nausea and dizziness, pupil dilation, and loss of appetite. Motor changes include tremor, muscle weakness, and ataxia. Mushroom poisoning from psilocybin use can begin within twenty minutes and last for six hours, causing nausea, vomiting, and excessive sleepiness. Increased respiratory rate and shallowness of breathing are particular to PCP and ketamine, and PCP doses greater than 5 mg can induce a dangerous reduction of blood pressure, heart rate, and respiratory rate.
Risk of death from overdose is twofold, through suicidal psychologic impairment of judgment and body dysregulation. At extremely high doses, hallucinogens cause deadly hyperthermia and seizure. Anesthetic nervous system sedation causes coma and dangerously low heart and respiratory rates. Spontaneous muscle contractions lead to muscle breakdown and kidney overload.
Delayed and Prolonged Effects
After the initial trip, adverse psychological and physical effects of drug use last from hours to days. The sense of detachment and the prolonged psychological changes after a trip ends can lead to panic and increased risk of suicide with any drug in the class. Depression, memory loss, visual changes, and long-term psychoses are not uncommon after even a single trip, particularly with LSD or psilocybin. Users with a history of psychiatric disorders more often experience depression and psychoses that can become more pronounced following hallucinogen use.
After use of anesthetic hallucinogens, paranoia and schizophrenic episodes may develop, regardless of the prior state of mind or drug experience. Up to 50 percent of PCP users experience anxiety within forty-eight hours of drug use, and PCP can alter thought, speech, and memory for up to one year after a trip.
Perhaps the most characteristic delayed hallucinogenic response is the psychologic flashback experience. Flashbacks occur primarily after LSD, peyote, or psilocybin use and can occur spontaneously or can be triggered by fatigue, stress, or the use of certain drugs (such as alcohol, barbiturates, and marijuana). These sudden episodes can develop after just a single trip, can occur once or multiple times, and can develop within days or years. A hallucinogenic flashback may repeat the initial trip or may manifest as a visual hallucinatory experience, although any distortion is possible.
Although hallucinogens are considered nonaddictive, serotonin-related tolerance among the plant hallucinogens develops, and dissipates, quickly. Conversely, chronic PCP use leads to addictive cravings and drug-seeking compulsions. Physical dependence on PCP is rare, but PCP may induce reduced heart and respiratory rates as withdrawal.
Long-term Impairment
Semipermanent psychological and physical impairments occur as extensions of the drug assault. LSD in particular is associated with psychotic episodes years after drug use has ended; plant hallucinogens induce long-lasting visual changes, disorganized and irrational thought patterns, and fluctuating depression and mania. Conversely, PCP mediates continued depressive symptoms and long-term memory loss.
The flashbacks from natural hallucinogens can recur for up to five years in chronic users and may impact psychological health for much longer. Hallucinogenic persisting perception disorder, or HPPD, is a psychiatric diagnosis of hallucinatory flashbacks that persist for five or more years after a single trip. HPPD flashbacks occur most frequently in persons with a history of LSD use and are typically experienced as repeated false visual sensations and alterations; the effects can be confused with symptoms of neurologic stroke or brain tumor in otherwise healthy persons.
Bibliography
Cunningham, Nicola. “Hallucinogenic Plants of Abuse.” Emergency Medicine Australasia 20 (2008): 167–74. Print.
"How Do Hallucinogens (LSD, Psilocybin, Peyote, DMT, and Ayahuasca) Affect the Brain and Body?" National Institute on Drug Abuse. NIH, Feb. 2015. Web. 27 Oct. 2015.
Laing, Richard R., ed. Hallucinogens: A Forensic Drug Handbook. San Francisco: Elsevier, 2003. Print.
Substance Abuse and Mental Health Services Administration. “NSDUH Report: Use of Specific Hallucinogens, 2006.” Rockville, MD: Author, 2008. Print.
Wu Li-Tzy, et al. “Recent National Trends in Salvia divinorum Use and Substance-Use Disorders among Recent and Former Salvia divinorum Users Compared with Nonusers.” Substance Abuse Rehabilitation 2 (2011): 53–68. Print.
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