Recognizing a crisis

Criterion 36 begins the crisis intervention function by examining recognition. A facilitator needs to notice physical, psychological, and existential distress, consider what may be contributing to it, and identify when qualified help is needed. Intensity alone cannot tell us whether an experience is safe or whether it will later be beneficial. This module combines research on challenging experiences with observation of the person and the setting. Criteria 1 and 2 provide the pharmacological safety background; Criterion 37 develops the immediate response, and Criterion 38 addresses later integration of a crisis event.

Learning Objectives

By the end of this module, the trainee will be able to:

• Define a client crisis and state why recognition is the first competency of crisis intervention.
• Recognize physical warning signs, including the pharmacological hazards discussed in Criteria 1 and 2.
• Recognize the elements of a psychological crisis, including panic, dissociation, and acute risk to self.
• Recognize the elements of a spiritual or existential crisis and why it can carry lasting harm if mishandled.
• Use research on challenging experiences to inform observation while recognizing that survey findings cannot determine whether an individual is safe.
• Recognize how the environment, group, and facilitator's actions may contribute to distress.
• Integrate trained knowledge with attuned observation of subtle cues.
• Recognize when qualified medical or mental health help is needed and explain how recognition leads to the response developed in Criterion 37.
• Recognize sensory overload or irritation, describe the response to environmental adjustments, and identify when sensory reminders need further assessment.

Key Terms

Crisis. Acute physical or emotional distress that presents a risk of harm or overwhelms the person's available capacity and support, requiring a timely response.

Recognition. Noticing signs of distress or danger, considering the circumstances, and identifying the need for further assessment or immediate help.

Challenging experience. An experience involving difficulties such as fear, grief, physical distress, or a sense of losing one's mind or dying (Barrett et al., 2016). The term describes the experience; it does not establish its safety or eventual outcome.

Physical crisis. A medical emergency, including seizure, loss of consciousness, dangerous changes in vital signs, severe vomiting with dehydration, or an allergic reaction affecting breathing. Criteria 1 and 2 address relevant drug interactions and cardiac hazards.

Psychological crisis. Acute psychological distress such as a panic attack, traumatic flashback, dissociation, or the emergence of thoughts of self harm or suicide, which calls for recognition and appropriate escalation.

Existential or spiritual crisis. Acute distress in the domain of meaning and selfhood, such as ego dissolution accompanied by terror, persecutory or frightening visions, or overwhelming shame or despair, which requires skilled recognition and containment.

Discernment. Judgment about the person's condition and need for assistance, informed by physical signs, communication, the course of distress, risk of harm, and the available support.

Escalation. Obtaining qualified medical or mental health assistance when the person's needs exceed the facilitator's training, role, or available resources.

Sensory overload. A descriptive term for input that a person finds difficult to tolerate or organize, such as overwhelming sound or simultaneous demands; it does not identify the cause of distress or exclude a medical condition.

Core Teaching

Recognizing distress and danger

Recognition begins with attending to the person and noticing changes. A facilitator may see rapid breathing, confusion, withdrawal, agitation, or an expression of despair. Ask what is happening, observe the physical signs, and consider the setting and the person's known history. Several kinds of distress may occur together, and an apparent psychological explanation does not rule out a medical problem.

The response needs to follow what is observed and the level of uncertainty. Intense crying may occur during a meaningful experience, but that possibility does not establish that the person is safe. Quietness can also conceal a serious concern. Use the program's emergency procedures and seek qualified assessment when there are warning signs or uncertainty about safety. Recognition should lead promptly to the help the person needs.

Establish what is different from the person's earlier presentation. Ask staff who have been with them and note the timing of the change. A participant who has been quiet throughout the session presents a different observation from someone who abruptly stops responding after being conversational. Describe the change without assuming its cause. The team may need information about the substance, timing, other medications or substances, and any known medical concerns when obtaining qualified help.

Use ordinary language in the first communication. “They stopped answering two minutes ago” or “They are saying they intend to hurt themselves” is more useful than “They are having a bad trip.” A general label can obscure the event that requires attention. Communicate what is known, what remains uncertain, and which staff member is currently with the person. This supports a prompt handoff while the designated responder assesses the situation.

Physical warning signs

Physical warning signs include dangerous changes in vital signs, abnormal breathing, seizure, loss of consciousness, severe vomiting with dehydration, and signs of an allergic reaction affecting the airway. A racing heart or elevated blood pressure needs to be considered in context by someone qualified to assess it. Staff preparation should include emergency procedures, appropriate first aid training, and access to medical assistance suited to the setting and its risks.

Criteria 1 and 2 discuss serotonin toxicity and the cardiac hazards associated with ibogaine. Relevant medication and substance information must be available to the clinical team. Agitation accompanied by rising temperature, muscle rigidity or twitching, exaggerated reflexes, heavy sweating, and a rapid heart rate can indicate a serious medical problem, including serotonin toxicity (Dunkley et al., 2003). These signs call for urgent medical assessment. Facilitators should recognize warning signs and obtain help within their role; this module does not train them to diagnose or manage these conditions independently. Serotonin toxicity ranges from mild manifestations to severe, life threatening illness; severe toxicity is a medical emergency. Hunter criteria were derived and validated in serotonergic overdose populations and are not universally validated across therapeutic or psychedelic exposures. In nonmedical facilitation settings, suspected toxicity warrants prompt medical assessment without independent facilitator grading or treatment (Chiew & Isbister, 2025).

Psychological distress and risk to self

Panic can involve rapid breathing, shaking, and a sense of impending death. Traumatic flashbacks may bring a feeling that a past event is happening again. Dissociation may involve disconnection, confusion, or reduced responsiveness. Observe carefully and ask what the person can describe. Similar signs may have medical causes, so a familiar psychological presentation should not end the assessment of safety.

Statements about suicide, self harm, or being unable to continue require a prompt response. Take the disclosure seriously, maintain support, and involve qualified help according to the situation and the program's procedures. A formal clinical risk assessment belongs with someone trained and authorized to conduct it. General reassurance alone is insufficient when a person has expressed a risk of harm.

Ask directly when a statement raises concern about self harm. A person saying, “I cannot go on,” may be expressing exhaustion, despair, or an intention to end their life. Clarify what they mean and obtain the appropriate qualified assessment. Follow the emergency plan when there is immediate danger or uncertainty about safety. Spiritual language, apparent calm, or a recent positive experience should not become reasons to dismiss the disclosure.

Also notice difficulties that appear after the acute effects have ended. Markedly disrupted sleep, escalating agitation, confusion, unusual behavior, or a reduced ability to manage basic needs can require prompt clinical attention. Ask about the course of the change and how the person is functioning. The facilitator's task is to recognize the concern and connect the person with the level of care needed, while leaving diagnosis and treatment decisions to the appropriate professionals.

Existential and spiritual distress

Some people experience terror as their ordinary sense of self changes. Others describe persecutory visions, overwhelming shame, loss of meaning, or despair they feel unable to bear. These experiences can be deeply distressing even when no obvious medical abnormality has been identified. Ask about what the person is experiencing and attend to how they are coping, communicating, and responding to support.

Avoid deciding for them that the experience is a spiritual breakthrough or that suffering is necessary for healing. Such interpretations can make it harder for the person to say they need help. Their immediate condition and safety guide the response. Spiritual language may be part of how they understand the event, while qualified psychological or medical care may also be needed.

What research on challenging experiences can tell us

Carbonaro et al. (2016) surveyed 1,993 people about their most challenging experience after taking psilocybin mushrooms. About 39% placed it among the five most difficult experiences of their lives, and 84% reported that they had benefited from it. About 11% reported putting themselves or others at risk of physical harm. Greater dose, difficulty, and duration were associated with risk, while physical comfort and social support were associated with lower risk.

The respondents selected themselves into a survey about difficult experiences. The percentages describe that sample, whose demographic range was limited; they do not give the incidence of harm among everyone who uses psilocybin. The authors also discuss the lower frequency of serious problems reported in screened and supported research settings. These findings give context for understanding difficulty and possible benefit. They cannot predict the outcome of a current episode or provide a clinical rule for deciding when to intervene.

During an episode, observe whether the person can communicate, whether distress is changing or continuing to intensify, and whether there are physical warning signs or an immediate risk of harm. These observations can help staff describe what is happening and decide what assistance to obtain. They are practical prompts, not a validated assessment tool. A verbal response does not rule out a medical emergency, and loss of responsiveness needs prompt assessment.

Continue reviewing the situation as it changes. A person who was managing a few minutes ago may now need more support. If safety is uncertain, obtain qualified help promptly. The detailed response and stabilization procedures are developed in Criterion 37.

A more recent review from Johns Hopkins examined adverse events in classic psychedelic studies. Hinkle et al. (2024) analyzed 114 studies involving 3,504 participants and found that serious events were uncommon in monitored research and clinical settings, while also identifying problems with detection and reporting. The review concerns selected populations and specific substances. Its findings support careful monitoring and better follow up; they cannot certify an individual participant as safe or be applied unchanged to every ceremonial setting.

Evans et al. (2023) examined extended difficulties in people specifically recruited because they had experienced them. Accounts included anxiety, existential struggle, and depersonalization or derealization that could persist beyond the session. This sample cannot provide a general incidence estimate. It does support asking about continuing distress and access to help after someone has gone home.

A follow up conversation can ask about sleep, daily responsibilities, distressing changes in perception, and whether the person feels able to remain safe. Ask about improvement as well as deterioration and record the course of any concern. A client may be grateful for the experience and reluctant to mention a problem for fear of seeming ungrateful. Make it clear through the questions and response that both parts of their account can be heard.

Considering the environment and relationships

Look beyond the person's internal experience when trying to understand distress. Loud music, crowding, uncomfortable temperature, movement in the room, or conflict between participants may contribute. A facilitator's words, touch, proximity, or manner may also be frightening or intrusive. Ask what the person needs when they can communicate, and notice whether distress changes in response to the surroundings.

Environmental adjustments may be useful while assessment and support continue. They should not delay urgent care or become a reason to dismiss physical warning signs. Recognizing a contribution from the room, group, or facilitator gives the team something concrete to address as part of the response.

Consider whether an interaction with staff contributed to the distress. A participant may react after an unwanted touch, an interpretation, or an attempt to prevent them from expressing a preference. Another team member may need to take over contact while the situation is assessed. Record the participant's account and follow the appropriate safeguarding or complaint procedure. The possibility of a pharmacological contribution does not remove the need to examine conduct in the room.

When a participant cannot explain what is wrong, use the information already gathered during preparation. A known sensitivity to noise, a preferred way of being approached, or an agreed communication signal may help staff offer support. Continue assessing safety as adjustments are made. Improvement after lowering music or changing staff proximity is useful information, but it should be considered alongside the full presentation and any need for clinical assessment.

Recognizing sensory overload and irritation

Notice what changed just before the distress became apparent. Was there a rise in volume, a new song, smoke entering the room, a change in lighting, or someone moving close? Ask one concrete question at a time, such as, “Is the sound uncomfortable?” Allow time for an answer or the signal agreed during preparation. Covering the ears, pulling away from a blanket, squinting, or trying to remove an eyeshade can suggest something to check. Those actions have several possible explanations, so describe what you see and seek the person’s account when possible.

Music can contribute to the difficulty. Participants in Kaelen et al. (2018) described unwelcome effects that included fear, discomfort, and feeling that the music was intrusive or mismatched to their experience. A facilitator should be willing to pause or adjust the music when the participant requests it. Several staff talking over the sound may add to the demand on someone who is already struggling to respond. Have one person make contact, keep questions brief, and explain any necessary movement or change in the room.

Smoke also requires a physical assessment. Ho et al. (2005) found increased respiratory and irritative symptoms in workers exposed to incense in temples. If a participant begins coughing after incense or sage is lit, stop the burning and attend to the exposure while checking their condition. Fear may accompany airway irritation. Staff should not conclude that difficulty breathing is anxiety because the person also appears frightened. Severe or worsening breathing difficulty, collapse, chest pain, or impaired responsiveness calls for urgent medical help through the program’s emergency procedures.

When there is no immediate danger, make a clear, agreed adjustment and observe what follows. Lower or pause the music, remove the source of an odor, or offer a supported move to a quieter place. Avoid introducing several new sensory techniques at once. Someone distressed by smell may find an essential oil equally unwelcome; someone frightened by touch may need more space. Where an exposure is clearly hazardous or emergency help is needed, act promptly rather than waiting to test each possible explanation. Continue monitoring during any move, and make sure the person remains accompanied.

Record the sequence in ordinary language: “When the drumming became louder, the participant covered both ears and asked for it to stop. Staff paused the music. They then answered questions more easily.” Include symptoms that persisted and who assessed them. Improvement after an adjustment helps the team understand the event, but it cannot by itself exclude a medical problem. It is also possible for the sound to be upsetting while another condition needs treatment. Pass both observations to the person taking over care.

Sensory reminders after a frightening experience

Ask about reminders when following up after a difficult session. A participant may report that a particular song, smell, or room brings back fear or physical unease. Human research on aversive learning shows that an odor can acquire significance through its association with an unpleasant event (Li et al., 2008). This offers a possible explanation to explore without assuming that every later reaction has the same cause. Ask what happens, how long it lasts, and whether it is affecting sleep, ordinary activities, or the person’s ability to feel safe.

Pause any planned use of a cue that the participant finds overwhelming and arrange appropriate support. They do not need to replay the session music or encounter the same scent to complete integration. Repeatedly exposing someone to a distressing cue as an informal attempt to make them process the experience may exceed the facilitator’s competence and the person’s agreement. Persistent or disabling reactions require qualified assessment. Criterion 26 discusses optional use of sensory reminders, and Criterion 38 develops the later integration of a crisis event.

Combining training with observation

Training helps the facilitator recognize warning signs and understand when to seek help. Close observation adds information about this person at this moment: a change in tone, posture, eye contact, movement, or responsiveness. Agitation and unusual stillness both deserve attention. Compare what you notice with the person's earlier presentation and share specific observations with the team.

Remain clear about your role. Recognition involves identifying a concern and bringing in the appropriate support. Diagnosis, formal risk assessment, and emergency treatment require the relevant qualifications. Prepare for that handoff before a crisis occurs so that uncertainty about roles does not delay care.

Before a handoff, gather the information already available without delaying urgent help. Give the responder the person's observed condition, the time course, known substance exposure, relevant health information, and the support provided so far. Include their response to that support. When details are unknown, say so plainly. Staff should avoid guessing at a dose or diagnosis to make the account sound complete.

Afterward, ensure that someone is responsible for checking the outcome and arranging any further support. The program can review whether a concern was noticed promptly, whether responsibility was clear, and whether communication helped the response. Record changes to practice where needed. Criterion 37 develops the immediate response, and Criterion 38 addresses later integration; the observations made here provide information for both.

Changes that become apparent after departure

Crisis recognition continues after the ceremony. Ask about changes in sleep, activity, orientation, and the person’s ability to manage ordinary tasks. Someone may describe feeling unusually energized while sleeping very little, making rapid commitments, or becoming increasingly difficult to interrupt. Record the change from their usual pattern, when it began, and any immediate danger. Arrange prompt qualified assessment when the pattern raises concern; the facilitator need not determine a diagnosis before seeking help.

The bipolar disorder survey by Morton et al. (2023), discussed in Criterion 32, included reports of sleep difficulties and increased manic symptoms after psilocybin use. Its findings cannot be applied as a diagnostic rule. They reinforce the need to ask about sleep and mood when following up, alongside the broader assessment of persistent difficulties already described in this module. Immediate danger, severe confusion, or inability to maintain basic safety requires urgent help through the applicable emergency pathway.

During a handoff, describe what was observed, what the participant reported, and what remains unresolved. Include relevant exposures, environmental changes, and any response to adjustments, as well as the timing of symptoms. State who is taking responsibility for the next contact and confirm that the person can reach the agreed service. If the participant reports an intrusive interaction with staff, preserve that account and arrange an appropriate review; a quiet room or a calmer presentation does not settle the concern. Criteria 31 and 34 cover complaints and continuity of care.

Clinical and Decision Tools

Tool 1. The three domains of crisis, and what to recognize

Use the domains to organize observations. They can overlap, and physical warning signs require prompt attention regardless of how the person describes the experience.

Tool 2. Findings from the survey of challenging experiences

The findings below describe 1,993 self selected respondents reporting their most challenging psilocybin mushroom experience (Carbonaro et al., 2016).

Tool 3. Observations that inform assessment

These prompts help describe the person's condition. They do not diagnose a crisis, establish that an experience is therapeutic, or replace qualified assessment.

Tool 4. Recognize sources beyond the individual

Consider what the room, group, and facilitator may be contributing while continuing to assess the person's condition.

Tool 5. Recognition checklist

Review the observations, immediate risks, and need for qualified assistance. Use the program's emergency procedures when indicated.

Worked Example: Recognizing Across the Line

This fictional example illustrates observation and the decision to seek further help. It does not provide a medical assessment protocol.

Context: Two hours into a group session, a participant who took a high dose is crying out, rocking, and saying over and over that they are dying and disappearing. A facilitator must recognize what this is.

Physical observation: The participant is breathing rapidly and can answer a brief question. The facilitator informs the designated clinical staff and follows the program's procedures for assessment. Responsiveness alone does not establish medical safety.

Understanding the distress: The facilitator asks what the participant means by “dying” and listens to their answer. The words could describe several experiences and do not, by themselves, establish ego dissolution or rule out a physical problem.

Checking communication: The facilitator says, “I'm here. Can you hear me? Can you tell me what you need?” They observe the response and continue communicating calmly. Touch requires the relevant consent and should not be assumed.

Sensory observation: The participant points toward the speaker and says the sound feels threatening. Staff pause it at their request while clinical assessment continues. Another team member checks for smoke, strong fragrance, and crowding. The team records any change in distress and breathing and remains alert to symptoms that continue after the room is quieter.

Ongoing observation: The team watches the course of distress, communication, physical signs, and any risk of harm. They provide support and reassess as the situation changes.

Seeking urgent help: If physical warning signs appear, the participant becomes unresponsive, risk of harm emerges, or safety remains uncertain, staff obtain qualified assistance promptly and follow the emergency plan. Criterion 37 develops the response.

Case Vignettes

For each vignette, identify the concern, consider the client’s needs, and describe how you would respond. Use the companion worksheet when available, or record your responses separately.

Vignette A

A participant taking an SSRI receives an ayahuasca preparation containing MAO inhibiting harmala compounds without an adequate medication review. They become agitated and hot, with visible muscle twitching, a rapid heartbeat, and heavy sweating. A facilitator notices but assumes it is an intense emotional release. This is a compatible exposure requiring urgent medical assessment; the concern cannot be inferred from an SSRI plus any psychedelic alone.

Guided questions: Which signs suggest a possible medical emergency? What relevant interaction history needs to be communicated to medical staff? What should the facilitator do immediately within the emergency plan?

Vignette B

A client weeps hard, shakes, and cries out during a session as they move through grief. A newer facilitator, alarmed by the intensity, moves to stop the experience and bring the client out, convinced they are witnessing a crisis.

Guided questions: What additional information is needed about the person's physical condition and response to support? Why does intensity alone fail to establish either danger or benefit? How can staff offer support while assessing safety?

Vignette C

A client becomes silent, blank, and unreachable, not responding to their name or to gentle contact, and remains that way well beyond a passing moment. The facilitator, seeing no dramatic signs, assumes the client is simply going deep inward.

Guided questions: What possible explanations require qualified assessment? Why is the loss of responsiveness a concern even without agitation? What should the facilitator do next?

Vignette D

During integration, a client quietly says they do not see the point of going on and that everyone would be better off without them. The facilitator, wanting to keep the space positive, reassures them warmly and moves the conversation along without acting on what was said.

Guided questions: What concern did the client express? What support and qualified assessment are needed? How does recognition lead to the response developed in Criterion 37?

Vignette E

In a crowded, loud group room, a participant becomes increasingly panicked and overwhelmed. The facilitator focuses entirely on the participant's internal psychology and never considers that the sensory chaos of the environment is driving the escalation.

Guided questions: What environmental conditions may be contributing? What can staff adjust while continuing assessment and support? What signs would require additional help?

Role Play and Practice Scripts

Practice in pairs, then switch roles. Describe observations, communicate calmly, and state when you would obtain qualified help. Use the response procedures developed in Criterion 37 when extending the exercise.

Checking communication

The partner appears distressed. Say, “I'm here with you. Can you hear me? Can you tell me what's happening?” Notice whether they respond and what they can communicate. Discuss what further information you would need; a response alone does not establish safety.

Speaking calmly during assessment

“I can see this is frightening. I'm staying with you while we get some help. Tell me what you can about what you're feeling.” Practice a steady tone and short questions. Avoid promising safety or predicting how the experience will end.

Responding to a disclosure of risk to self

The partner says they do not want to be alive. Respond, “Thank you for telling me. I'm taking this seriously. I'll stay with you while we get someone who can help assess what you need.” Practice activating the appropriate support and emergency procedures within your role.

Scanning the whole situation

Observe the person's physical signs, communication, and surroundings. Describe one concern to your partner using specific observations, such as, “Their breathing has become faster, and the noise in the room seems to be increasing their distress.” State what help you would seek and what environmental change could be considered while assessment continues.

Checking a sensory contribution

The partner describes coughing and panic after incense was lit. Practice stopping the exposure, calling for the appropriate assessment, and describing the timing to another staff member. Repeat the exercise with a request to stop music and no reported physical symptom. Discuss what you could adjust in each case and what would make you obtain urgent help. Simulate the situation verbally, without smoke or distressing sensory exposure.

Changes that become apparent after departure

At follow up, a participant reports very little sleep and rapidly escalating plans. Practice describing the change, asking about immediate safety, and arranging qualified assessment. Then give a brief handoff that separates observed facts, the participant’s account, and questions still needing assessment.

Self Assessment and Reflection

Knowledge check

Define a client crisis and explain why recognition is the first competency of crisis intervention.

Name physical warning signs and describe the relevant medication interaction and cardiac hazards discussed in Criteria 1 and 2.

Name the psychological presentations, and state the scope boundary around expressed risk to self.

Describe an existential or spiritual crisis and why a medical checklist alone can miss it.

Describe the findings and sampling limits of Carbonaro et al. (2016). Explain why the survey cannot determine whether a current episode is safe.

List observations that help describe a person's condition and identify the need for qualified assessment.

Describe when to obtain qualified assistance and how that decision leads to the response developed in Criterion 37.

Someone becomes calmer when the music stops but continues to report difficulty breathing. What does the improvement tell you, what remains unresolved, and what action is needed?

Reflection

Where is your own recognition weakest, the medical signs, the psychological ones, or the existential ones? How will you strengthen it?

How do you respond to intense distress? Where might you act too quickly on an assumption, or overlook a warning sign? What training or supervision would help?

How do you tell, in yourself, the difference between calm vigilance and anxious hypervigilance? Which serves recognition?

Summary

Recognizing a crisis requires attention to physical signs, psychological distress, the person's experience of meaning and selfhood, and the circumstances around them. These domains may overlap. Changes in communication, responsiveness, behavior, or vital signs need to be considered together. Environmental conditions and the facilitator's own actions can also contribute to distress.

Research on challenging psychedelic experiences describes both reported benefit and risk of harm, but survey findings cannot establish the safety or likely outcome of an individual episode (Carbonaro et al., 2016). Neither intensity nor calmness is sufficient on its own. Observe, ask brief questions when the person can respond, communicate concerns to the team, and obtain qualified help when indicated or when safety is uncertain. The facilitator works within their training and role, with immediate response developed in Criterion 37 and later integration in Criterion 38.

References

Sources

Barrett, F. S., Bradstreet, M. P., Leoutsakos, J.-M. S., Johnson, M. W., & Griffiths, R. R. (2016). The Challenging Experience Questionnaire: Characterization of challenging experiences with psilocybin mushrooms. Journal of Psychopharmacology, 30(12), 1279–1295. https://doi.org/10.1177/0269881116678781

Carbonaro, T. M., Bradstreet, M. P., Barrett, F. S., MacLean, K. A., Jesse, R., Johnson, M. W., & Griffiths, R. R. (2016). Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences. Journal of Psychopharmacology, 30(12), 1268–1278. https://doi.org/10.1177/0269881116662634

Dunkley, E. J. C., Isbister, G. K., Sibbritt, D., Dawson, A. H., & Whyte, I. M. (2003). The Hunter Serotonin Toxicity Criteria: Simple and accurate diagnostic decision rules for serotonin toxicity. QJM, 96(9), 635–642. https://doi.org/10.1093/qjmed/hcg109

Evans, J., Robinson, O. C., Argyri, E. K., Suseelan, S., Murphy-Beiner, A., McAlpine, R., Luke, D., Michelle, K., & Prideaux, E. (2023). Extended difficulties following the use of psychedelic drugs: A mixed methods study. PLOS ONE, 18(10), e0293349. https://doi.org/10.1371/journal.pone.0293349

Hinkle, J. T., Graziosi, M., Nayak, S. M., & Yaden, D. B. (2024). Adverse events in studies of classic psychedelics: A systematic review and meta-analysis. JAMA Psychiatry, 81(12), 1225–1235. https://doi.org/10.1001/jamapsychiatry.2024.2546

Ho, C.-K., Tseng, W.-R., & Yang, C.-Y. (2005). Adverse respiratory and irritant health effects in temple workers in Taiwan. Journal of Toxicology and Environmental Health, Part A, 68(17–18), 1465–1470. https://doi.org/10.1080/15287390590967405

Kaelen, M., Giribaldi, B., Raine, J., Evans, L., Timmerman, C., Rodriguez, N., Roseman, L., Feilding, A., Nutt, D., & Carhart-Harris, R. (2018). The hidden therapist: Evidence for a central role of music in psychedelic therapy. Psychopharmacology, 235(2), 505–519. https://doi.org/10.1007/s00213-017-4820-5

Li, W., Howard, J. D., Parrish, T. B., & Gottfried, J. A. (2008). Aversive learning enhances perceptual and cortical discrimination of indiscriminable odor cues. Science, 319(5871), 1842–1845. https://doi.org/10.1126/science.1152837

Morton, E., Sakai, K., Ashtari, A., Pleet, M., Michalak, E. E., & Woolley, J. (2023). Risks and benefits of psilocybin use in people with bipolar disorder: An international web-based survey on experiences of ‘magic mushroom’ consumption. Journal of Psychopharmacology, 37(1), 49–60. https://doi.org/10.1177/02698811221131997

Related workbook material

Serotonin toxicity and cardiac hazards: Criteria 1 and 2.

Acute concerns and referral: Criterion 20.

Preparation and the setting: Core Function V and the setting criteria.

Immediate response and stabilization: Criterion 37.

Later integration of a crisis event: Criterion 38.

Evidence and application

Carbonaro et al. studied a self selected sample reporting difficult experiences. Its percentages cannot be used as incidence estimates for all users or as a clinical decision rule. Barrett et al. developed a questionnaire characterizing challenging experiences. The observation prompts in this module are teaching aids and do not replace qualified assessment.

The sensory discussion draws on participants’ accounts of music during psilocybin treatment, occupational research on incense exposure, and human laboratory research on odor learning. These studies do not establish a sensory test for deciding whether someone is medically safe. The observation exercises require application alongside the program’s emergency procedures and qualified assessment.

Chiew, A. L., & Isbister, G. K. (2025). Management of serotonin syndrome (toxicity). British Journal of Clinical Pharmacology, 91, 654–661. https://doi.org/10.1111/bcp.16152