Although phencyclidine and other hallucinogens make up two separate substance use categories, they are frequently studied and discussed together and are often all grouped together under the term “hallucinogens”. In fact, across the two disorders, there are at least four distinct genres of substances (phencyclidines, phenylalkylamines, indoleamines, and ergolines), not to mention several outliers. The common thread across all these substances is that they alter users’ perceptions of reality in several ways.
Using phencyclidine (‘PCP’, ‘angel dust’) causes aggression and erratic behavior. Users have reduced judgment, and they are frequently confrontational and dangerous. They tend to appear visibly agitated and tense. They also have an altered gait, speech pattern changes, and decreased sensitivity to pain. Chronic phencyclidine or ketamine (‘special K’) use can lead to persistent psychotic states lasting days or weeks beyond the last dose of the drug. These appear very similar to an exacerbation of Schizophrenia. Patients have hallucinations, delusional and disorganized thoughts, separation from reality, agitation, reduced speech, emotional changes, impaired motivation, and social withdrawal. Long term phencyclidine use can also cause speech and cognitive difficulties, depression, anxiety, and suicidality.
MDMA (3,4-methylenedioxymethamphetamine, ‘ecstasy’ or ‘molly’) originally developed a reputation as a “club drug”, first seeing frequent use at raves (large, overnight dance parties). It acts not only as a stimulant, but also makes users more empathic and emotionally open. Users experience increased energy, sexual arousal, euphoria, altered senses, and, most classically, increased sensitivity and intimacy with others. MDMA’s other immediate effects are similar to those of amphetamines (to which MDMA is closely related), such as restlessness, muscle tension, dry mouth, teeth grinding, increased heart rate and blood pressure, and high body temperature. Higher doses lead to hallucinations, agitation, anxiety, temporary psychosis, and disorganized and bizarre behavior. A ‘hangover’ period follows in the next 24-48 hours characterized by depression, decreased energy, and lack of concentration.
Chronic MDMA use damages serotonin-releasing cells in the brain, reducing both their numbers and their activity. Brain wave activity in these patients appears similar to that of dementia patients. Patients suffer significant cognitive problems (impaired memory, organization, and problem-solving), and the severity is directly proportional to the amount of MDMA that was used. Patients also deal with long lasting mood and behavioral changes, such as treatment-resistant depression, panic disorder, and impulsivity. They can also experience flashbacks characterized by paranoia, hallucinations, and psychosis.
Hallucinogens other than phencyclidine and MDMA manipulate serotonin levels to create auditory, visual, and tactile hallucinations. User’s senses intensify, and they experience changes in perception of the passage of time. The different compounds can bring about emotional reactions, agitation, relaxation, and even metaphysical experiences. The effects of LSD (lysergic acid diethylamide, ‘acid’), psilocybin (‘magic mushrooms’, ‘shrooms’), and peyote cactus take up to 1.5 hours to begin and can last up to 12 hours. Those of Salvia divinorum and DMT (dimethyltryptamine) start within minutes and last up to an hour.
Long term users of these drugs (though most evidence concerns LSD specifically) can develop two different disorders: chronic psychosis and Hallucinogen Persisting Perception Disorder (HPPD). Chronic psychosis mimics schizophrenia and includes paranoia, hallucinations, disorganized thought patterns, and mood issues. HPPD occurs long after the last drug use and consists of episodes (formerly referred to as ‘flashbacks’) of perceptual changes and hallucinations similar to those experienced when the drug is taken.
Causes and Risk Factors
Not so common
The prevalence of hallucinogen use has been on the rise since the late 1980s. However, relative to other drugs, hallucinogens remain far less common. About 1.5% of Americans report using hallucinogens in the past year, and MDMA accounts for about half of that. Far less than 1% of Americans meet criteria for a hallucinogen (phencyclidine or other) use disorder in a given year.
Not so frequent
About 20% of Americans will use hallucinogens at least once in their lives. However, the number of people who use them on a regular basis is much lower. The transition from adolescence to adulthood (and the significant increase in independence) presents the time of biggest risk for using these drugs. Even still, only about 1.8% of 18-25 year olds (the highest of all age groups) have taken hallucinogens in the past month. To compare, for the same age range, the past-month use rates are 58.3% for alcohol and 19.8% for marijuana.
Low addiction rates
Only about 2-3% of first-time hallucinogen users develop a use disorder within two years. Generally in the addiction literature, most hallucinogens are not as prone to causing use disorders as other drugs, such as alcohol and opiates. The exception to this rule is MDMA, most likely because of its stimulant-like effects.
MDMA and brain damage
Despite abundant evidence regarding the brain damaging effects of MDMA, most users view the drug as safe. This may explain why MDMA users, more than users of other hallucinogens, report tolerance and persistent use in the face of negative health consequences. Furthermore, MDMA use itself is a risk factor for other hallucinogen use because users want a drug with more powerful hallucinogenic effects than MDMA.
Instead of using hallucinogens on a daily or near daily basis, they are most commonly used a few times a month, often at parties and social events. For this reason, drugs in this category are often referred to as “club drugs”.
Mood and hallucinogens
Demographics of users of different hallucinogens are similar across the board, save for a few unique traits. MDMA users are more likely to have been depressed or anxious during childhood. Heavy LSD use can cause depression and risky sexual behaviors in young women. It is also accompanied by alcohol, tobacco, and marijuana use, and LSD appears to be a terminus in the progression through these substances.
Diagnosing Phencyclidine Use Disorder and Other Hallucinogen Use Disorder
What are all these different drugs?
Phencyclidine and its relative, ketamine, were originally medical anesthetics that induce hallucinations and feelings of separation from reality at high doses. Other Hallucinogen Use Disorder includes all hallucinogens except phencyclidine and its relatives. The most recognizable drugs are MDMA and LSD, both of which were originally meant to help with psychotherapy.
What do they come from?
MDMA, and its less common, less potent sister drug, DOM (2,5-dimethoxy-4-methylamphetamine), are stimulants that have hallucinogenic effects. LSD and mescaline are both derivatives of plants. LSD is from the ergot fungus, and mescaline comes from the peyote cactus. Many of the other, less common hallucinogens are plants in their raw form: psilocybin mushrooms, morning glory seeds, Salvia divinorum, and jimsonweed.
What do they look like?
People take most of these drugs orally, as crystalline powders, liquids, or pills. LSD usually appears on paper (‘blotter paper’). Psilocybin mushrooms, jimsonweed, and morning glory seeds come in their raw plant form. Salvia divinorum, DMT, and sometimes phencyclidine are smoked.
Diagnosis requires at least two symptoms over the course of one year.
- Patients use increasing amounts of hallucinogens or use for longer than originally intended
- They want or try to cut down but can’t
- They spend inordinate amounts of time finding, using, and recovering from hallucinogens
- Patients have a strong drive to continue using hallucinogens
- Hallucinogen use causes problems in major life domains, such as education, work, and home life
- They continue to use hallucinogens even in the face of social and relationship issues
- Patients give up work obligations, hobbies, and friendships to use hallucinogens
- They use hallucinogens at times that put themselves and others in harm’s way
- They continue to use hallucinogens in spite of direct physical and mental health consequences
- Patients develop tolerance to hallucinogens, needing increased amounts to achieve the same high
There are no withdrawal symptoms for most hallucinogens. Heavy phencyclidine users can suffer a withdrawal syndrome of anxiety, agitation and hallucinations, which can require inpatient treatment. Increasing numbers of symptoms determines the severity of the disorder. Four or five symptoms qualify as a moderate case; it’s a severe case if there’s six symptoms or more. Patients are in early remission if they have had none of those criteria for at least three months but not more than one year. Late remission extends beyond one year.
Treating Phencyclidine Use Disorder and Other Hallucinogen Use Disorder
There are no medications that specifically treat abuse of phencyclidine, MDMA, LSD, or any other hallucinogens. Unfortunately, there are very few studies at all that focus on hallucinogen use treatment. Because very few people abuse only hallucinogens, use of these drugs is usually integrated into treatment of the other drugs patients use. Treatments address their tendency to produce psychoactive disorders that persist long after the drug has been used.
Hallucinogen Persisting Perception Disorder
HPPD has traditionally been associated with LSD, though there are a few reports of it occurring from psilocybin use as well. The small amount of evidence for treatment information on HPPD points to benzodiazepines and clonidine for mitigating symptoms. Results with antipsychotics, namely Risperdal (risperidone), are middling. Two small studies report that Risperdal was associated with aggravated symptoms of HPPD (especially increased anxiety) but another study demonstrated the opposite. Psychotherapy may be helpful in teaching patients skills for coping with symptoms.
Phencyclidine and disturbed behavior
Phencyclidine users often come to the ER after taking large doses of phencyclidine. These people are aggressive, paranoid, and affected by powerful hallucinations. Physicians use benzodiazepines to calm patients’ erratic behaviors and to ward off the rare seizures that accompany these situations. Providers also closely monitor the cardiac status of these patients because fatal abnormal heart rhythms can strike without warning. Phencyclidine can also cause prolonged states of violent psychosis that require hospitalization for weeks for treatment with antipsychotics.
MDMA and mood
Heavy MDMA use can cause chronic depression, anxiety with panic, and psychosis. Animal studies point to low serotonin levels caused by brain damage from MDMA. A few small studies and animal studies report successful treatment of this condition with serotonin-boosting medications, such as Prozac (fluoxetine).
Managing Phencyclidine Use Disorder and Other Hallucinogen Use Disorder
One of the most well-known dangers of MDMA use is hyperthermia (excessively high body temperature), which has lead to multiple deaths. These almost always occur at raves, the hot, extended dance parties whose attendees frequently consume MDMA. These conditions work in concert with MDMA, which, regardless of the ambient temperature, decreases the body’s ability to regulate temperature.
Those who choose to use MDMA in these environments should protect against hyperthermia by taking periodic breaks and drinking enough water (although overconsumption of water by users has also been fatal). Acute phencyclidine intoxication also poses the risk of hyperthermia and rhabdomyolysis (widespread muscle breakdown that leads to kidney damage). Emergency responders should avoid using physical restraints which can exacerbate these problems.
Partygoers at raves can find resources and information at booths of harm-reduction organizations like DanceSafe. DanceSafe provides hydration and guidance on how much is appropriate. Given that the forms of these drugs (pills, powders) make it impossible to know exactly what they contain, DanceSafe also has testing kits on hand so that users can have more accurate information before taking the drugs.
Many of these drugs are able to induce psychosis, a severe split from reality. Phencyclidine psychosis so accurately mimics Schizophrenia that the drug is often used to produce animal models of Schizophrenia. People in psychotic states can quickly become a danger to themselves and others. If you are with someone in this state, treat it like any other medical emergency. Furthermore, if someone you know has recently been diagnosed with schizophrenia or a similar disorder unexpectedly (no family or personal history, no warning signs), consider the possibility of a drug-induced psychosis.
Though not full-on psychosis, users can also have “bad trips”. These are negative drug use experiences characterized by anxiety, depression, and panic. If this occurs, sit with the person in a quiet, calm space. Bad trips can be associated with feelings that the state is permanent. Reassure them that how they are feeling is due to the drug and will subside soon.