Patient safeguarding during a psychedelic experience is critical. High doses of relatively selective serotonergic agonists such as psilocybin can produce altered cognitions and sensory perceptions, a sense of connectedness, awe, astonishment, and complex emotional and psychological phenomena as part of the drug effect (
1–
5). Heightened arousal, feelings of unease and restlessness, and anxious dissolution of the sense of self are also commonly described (
6). After the acute drug effects resolve, there may be additional adverse effects, such as false insights and revelations, mood fragility, and increased suggestibility (
7,
8). Finally, disappointment stemming from unrealistic expectations may result in hopelessness and treatment abandonment. Collectively, these elusive and potentially challenging experiences pose unique ethical considerations, including those related to obtaining and maintaining informed consent for treatment (
9). Therefore, psychedelic treatment requires concurrent and specialized support to safeguard against overwhelming distress and promote a meaningful and therapeutic experience.
Since the 1960s, research conducted with classic psychedelics has suggested that a safe and meaningful experience with psilocybin necessitates psychoeducation, preparation, and psychological support (
10–
13). In the past two decades, a number of models have been developed to provide adequate support for treatment with psilocybin (
14), commonly utilizing a format consisting of preparation, drug administration, and integration (
15). These approaches have ranged from the active delivery of psychotherapy following administration of a sub-psychedelic dose to the nondirective, supportive presence of a facilitator monitoring the participant as they autonomously navigate a full-dose experience. Recent clinical trials have favored the latter approach (
14), but ambiguity persists regarding the optimal method of support. This is partly due to the absence of standardized approaches to psychological support, a gap that needs to be addressed as the field matures and psilocybin treatment moves toward potential regulatory approval. Standardized approaches will allow for clearly delineated and empirically scrutinized components that can enable the assessment of how support is delivered and what its impact is on patient experience. These approaches should also include comprehensive training and supervision to ensure the quality of the support provided and, of particular relevance in the clinical research context, consistent delivery and data integrity.
The Compass Psychological Support Model (CPSM) was initially developed as part of the clinical development program of COMP360 psilocybin treatment for treatment-resistant depression (TRD). COMP360 psilocybin treatment consists of the administration of the investigational drug COMP360, a Compass Pathfinder Ltd (Compass) proprietary formulation of synthetic psilocybin, with psychological support. The CPSM was informed by a review of historical use of psilocybin in research and clinical settings (
16–
18), the current understanding of psilocybin’s mechanism of action (
19–
21), and selected evidence-based psychotherapeutic approaches (cognitive-behavioral therapy, process-experiential therapy, mindfulness, acceptance and commitment therapy, and focusing therapy) (
22). More recently, the CPSM was adapted following careful study of participant experiences from Compass’s phase 2b double-blind clinical trial of COMP360 psilocybin for TRD and other completed and ongoing sponsored and investigator-initiated studies (
23,
24).
This adaptation of the CPSM was also influenced by dialogues with regulators in the United States, European Union, and United Kingdom. The regulatory evaluation and approval framework is based on the assessment of the safety and efficacy of an investigational medicinal product. Clinical practices, such as any forms of psychological therapy, are not customarily assessed or controlled by health authorities regulating drug products. We interpret regulatory advice to require the necessary psychological support to be clearly specified (e.g., in a manual) and to be demonstrably provided in a way that is unlikely to bias the outcome of drug treatments. The CPSM has therefore been designed to meet these requirements as a baseline standard of care, safeguarding participants in trials of COMP360 psilocybin. This exclusive applicability within the domain of psilocybin treatment precludes the CPSM from operating as a stand-alone psychotherapy as commonly understood. As such, the CPSM is not an evidence-based treatment for depression or any other psychiatric conditions for which the efficacy of investigational psilocybin is being tested.
Here, we describe the principles and methods of the CPSM currently used in our phase 3 program comprising two multicenter randomized, controlled, double-blind studies, involving participants across Europe and North America, and designed to establish the safety and efficacy of COMP360 psilocybin treatment in TRD. We further outline the therapist training, mentoring, and fidelity assessment we have developed to ensure and measure the quality and consistency of the CPSM delivery.
The Compass Psychological Support Model
The CPSM consists of psychoeducation and the delivery of psychological support. It is delivered by specially trained mental health care professionals who possess an active license in good professional standing and have the relevant education, training, and/or experience in mental health, counseling, or psychological therapies (henceforth therapist). The CPSM is administered across three treatment stages: preparation, administration, and integration (
Table 1). In the preparation stage, the therapist provides psychoeducation and prepares the participant to navigate their experience in the administration stage safely and autonomously. During administration, the therapist allows the participant’s experience to unfold naturally, providing minimal intervention and acting as a safeguard. In the integration stage, the therapist supports the participant’s reflection on their experience without offering interpretations or solutions, while remaining vigilant to any persistent unusual beliefs or ideations of harm to self or others.
Psychoeducation
The unique psychedelic effects of psilocybin require specific preparation (
9). Psychoeducation is essential in helping participants understand and form appropriate expectations for what may be an ineffable, emotionally intense, and sensorily novel process. This in turn appears to help generate trust, mitigate anxiety during the administration session, and facilitate psychological safety overall.
Psychoeducation starts before and continues throughout preparation with the therapist. Through a dedicated platform, study participants are encouraged to review preparation materials covering psilocybin’s mechanism of action, effects, and safety profile; the treatment process; accounts from previous trial participants; and examples of skills that will be practiced during preparation. Providing educational materials ahead of the first session with a therapist reduces the risk of participants being exposed to misinformation on the potential effects of psilocybin from other sources. It also allows participants to review these materials at their own pace, leaving more time for a discussion of their questions with the therapist during the preparation stage. During the preparation sessions, the therapist ascertains the participant’s understanding, clarifying misconceptions, and exploring and managing expectations. In addition, the therapist describes the core elements of the CPSM, as well as the therapist and participant roles, setting the stage for a collaborative preparation process that underscores the pivotal nature of active participant engagement in advancing toward recovery.
Psychological Support
The CPSM is informed by the established concepts of “set” (the participant’s state of mind, including dominant thoughts, emotional valence, and level of arousal) and “setting” (the physical environment in which the drug is administered) (
11,
25–
27). Research has demonstrated that poor clinical outcomes are associated with experiential avoidance or intense and prolonged hyperarousal (
28), both of which may manifest following administration of psilocybin. The CPSM aims to help participants maintain a mindset likely to minimize the occurrence of such effects, by preparing them to engage with a range of experiences safely and autonomously without avoiding them or becoming overwhelmed, and by providing a calm, non-stimulating treatment environment. This is achieved through three key principles—trust and psychological safety, present-moment focus, and self-direction and autonomy—and corresponding methods described below.
Key principles.
Trust and psychological safety.
Trust in the therapist, the clinical trial process, and their own ability to navigate potentially challenging experiences is vital to the participant’s active engagement with treatment. During preparation, the therapist invites the participant to share information about their background, including the influence of their mental health condition on their functioning, significant life events, history of trauma, and facets of their culture and identity that could emerge during the administration session. This discussion creates an opportunity for the therapist to establish trust by showing genuine interest, empathy, unconditional positive regard for the participant’s struggles with mental illness, and appreciation for their willingness to participate in clinical research. The discussion of the psychoeducational material (described above) is an opportunity to strengthen the participant’s confidence in their therapist’s expertise. Trust and psychological safety are also a key consideration in the way the broader study team interacts with the participant. Finally, the CPSM continuously invites the participant to develop and trust their own ability to engage with intense and challenging experiences, with the goal of eventually addressing unhelpful cognitive, emotional, or behavioral patterns.
The role of the therapist in ensuring psychological safety—through regular check-ins on the participant’s state of mind and readiness to proceed with the different stages of treatment—continues in the integration stage. During this stage, therapists are trained to detect and manage the potential emergence of affective states (e.g., disappointment, despair, and worsening symptoms of depression) or persisting ideas that may be counterproductive to the participant’s desired long-term outcomes.
Present-moment focus.
Present-moment focus is believed to be foundational in reducing the risk of harmful or counterproductive experiential avoidance and maximizing therapeutic gain. Experiential avoidance, characterized by the difficulty of remaining present, with intense affective experiences of varying valence, has been implicated in the etiology and maintenance of mental health conditions, including TRD (
29,
30). During the administration of a psychedelic, experiential avoidance increases the risks of prolonged intense distress and associated adverse consequences, including severe anxiety, paranoia, and dissociation (
31). Equally, maintaining present-moment focus helps participants become aware of emerging thoughts, feelings, and physical sensations, including those that may have been previously avoided, thereby facilitating self-discovery and the potential for “emotional breakthrough,” found to be a robust predictor of recovery in psilocybin trials (
32–
34). Practicing present-moment focus is therefore a key objective of preparation, achieved through two methods. The first consists of asking the participant open-ended questions about their moment-to-moment cognitive, affective, and somatic states (particularly those associated with discomfort), as they share their experience with depression, key life events, or concerns about the treatment process. Asked intermittently throughout preparation, these questions do not aim to support participants in generating novel insights, as would be the case with typical psychotherapies. Instead, they model the type of curious, internal exploration that the participant will be encouraged to undertake during the administration session. This is also the purpose of the second method, which invites the participant to practice exercises, such as breath and body awareness, to be used during the administration session. Both methods support the participant in developing an accepting and inquisitive stance toward internal discomfort, which promotes a safe and tolerable administration session, as well as a meaningful self-discovery process during integration.
Self-direction and autonomy.
While patient self-agency is an important overarching goal of mental health treatment in general (
35), it matters even more in the context of psychedelic treatments. The psychedelic experience can make participants highly suggestible, and consequently vulnerable to undue therapist influence. In accordance with ethical guidelines, the CPSM aims to empower participants to set their own intention for the administration session and their participation in the study, and to autonomously navigate the administration session and generate insights and solutions. A pivotal component of the therapist selection and training process is the assessment of their ability and willingness to deliver this nondirective approach.
Empirical data suggest that setting an intention prior to administration is instrumental in directing the psychedelic experience (
36,
37) and thus aiding participants in achieving a clear sense of purpose for their treatment and participation. Explicitly revisiting intention at the commencement of the administration session reinforces the participant’s mindset of focus, purpose, and autonomy and supports sustained engagement with challenging content during the administration session.
The emphasis on participant agency becomes particularly prominent during the integration phase, which involves the participant-driven selection of salient themes from administration and the generation of subsequent insights. Therapists refrain from leading participants to a particular answer, solution, or path. They do not give advice, interpret the participant’s experience, or impose their values or agenda into the process. Instead, they support participants in adopting an inquisitive stance toward any emerging content. It is important to acknowledge that there are limitations to a nondirective therapist stance, whereby even the slightest, unintentional therapist responses, such as body language, tone of voice, facial expressions, or timing thereof, may influence the participant’s exploration process (
38). Nevertheless, this unequivocally contrasts with the therapist providing structured, intentional guidance. Participants are instead encouraged to determine the insights or behaviors that they would like to carry forward after their participation in the study, as integration continues to unfold through their own processing and actions in daily life.
Methods of support.
Establishing support strategies for the administration session.
In preparation, the therapist and the participant discuss possible support strategies to be implemented by the participant independently or with the therapist’s support when navigating challenging emotional shifts during the administration session. As described earlier, these may include experiential practices (e.g., breath and body awareness, visualization, and self-compassion) but also physical proximity (e.g., the therapist sits closer to the participant for a period of time, without the involvement of physical touch) or the use of verbal cues (e.g., “let go,” “be open,” “go in and through”).
The use of physical touch for the purpose of reassurance and grounding is another option that the therapist discusses during preparation. Simple touch can reduce anxiety (
16,
39), but it can also, in an altered state of consciousness, be misinterpreted or trigger memories of abuse. Therapists are trained to approach this topic ethically and openly, first explicitly stating that physical touch will never be sexual in nature and will only include physical contact on the arm, shoulder, or non-interlocking hands. If the participant is open to physical touch as a support strategy, asking for and relinquishing physical support is practiced during preparation. During the administration session, physical touch is only employed in the manner that has been agreed upon and consented to during preparation (
9). Here again, encouraging the participant’s sense of autonomy is essential in enabling them to confidently decline support that may, under the influence of psilocybin, be perceived as crossing their personal boundaries.
Following their discussion of possible support strategies, the therapist and participant collaboratively select and practice those that best fit the participant, as informed by their history, clinical presentation, and preferences. This support plan is reviewed and re-consented to by the participant at the beginning of the administration session, during which the therapist refrains from introducing new strategies.
Supporting challenging emotional shifts and emerging trauma during the administration session.
Emotions can shift quickly during the administration session (
16). Additionally, participants can have traumatic memories emerge (
16,
40). Distress that the participant can process without unreasonable struggle should be allowed to unfold naturally. Therapists are trained to differentiate these normative emotional shifts from intolerable, dissociative, or otherwise overwhelming emotional reactions, and determine whether active support is necessary. If so, they implement support strategies one at a time in accordance with the plan and boundaries established in preparation. In extreme cases in which psychological safety is at risk (i.e., presence of acute unmanageable anxiety, psychotic symptoms), evaluation by a psychiatrist and the administration of rescue medication (i.e., benzodiazepine anxiolytics [e.g., lorazepam], antipsychotic medications [e.g., risperidone]) might be required. Nevertheless, data suggest that with proper support, participants are often able to navigate intense emotionally or psychologically challenging phenomena, and the use of such intervention is rare (<1.5% of the sample that received the 25-mg dose in previous clinical trials [
23,
24]).
Managing low-intensity experiences and disappointment.
Some participants may report low-intensity administration experiences or notice little improvement in their symptoms following the administration session, irrespective of the dose received (which may include placebo or subperceptual, medium, or high doses of investigational COMP360 psilocybin). Subsequently, they may be at risk for experiencing despair or hopelessness due to unmet expectations. Therefore, in preparation, the therapist explores the participant’s expectations regarding administration and outcomes and discusses plans if those expectations are not met. In particular, the therapist emphasizes that the relationship between the perceived intensity of the experience and clinical outcomes is still being investigated (
23,
41).
Even when expectations are managed appropriately in preparation, participants having a low-intensity experience are more likely to be interactive during the administration session and thereafter express disappointment or anger. Therapists are trained to validate and make space for these experiences in ways consistent with the key principles of the CPSM and while maintaining clinical equipoise. This ensures that the delivery of the psychological support is consistent across all participants, regardless of the intensity of the experience and the assumptions the therapist or participant may have made about the dose received.
Therapist Training and Assessment of Fidelity to the CPSM
To guarantee the quality of the support provided to participants and maintain research data integrity in establishing the safety and efficacy of investigational COMP360 psilocybin treatment, it is imperative that the CPSM be delivered competently and consistently (i.e., with high fidelity). To our knowledge, there are no published studies or guidelines on ensuring and measuring fidelity for psychological support in psychedelic treatment. Therefore, fidelity to the CPSM is based on the current published best practices and recommendations for psychological interventions generally (
42–
45). In our phase 3 trials, fidelity is ensured through the manualization of the CPSM and our therapist training and mentoring programs, and it is assessed through a formalized rating process. (The results of the fidelity assessment were not available at the time of writing, as the phase 3 program was still under way.)
The therapist training program in the CPSM has been described previously (
22), and has evolved based on our experience from the phase 2b and other COMP360 psilocybin studies. Developed with expert input from trainers with extensive clinical experience in psychedelic research, it is designed to ensure the consistent delivery of the CPSM across multiple sites, regions, and languages in a clinical research setting. In addition to the CPSM techniques, the maintenance of clinical equipoise and compliance with Good Clinical Practice standards take center stage in the training.
Before qualified therapists participate in the phase 3 trials, they are trained using multiple methods, including online self-study, review of recordings from previous trials, experiential role-play, and group discussion (
Table 2). Therapists are trained to competency in knowledge of mechanisms of action and subjective effects of investigational COMP360 psilocybin, the theoretical framework of the CPSM, and the purpose and implementation of psychoeducation, key principles, and methods of supporting participants in CPSM. Therapist performance is further formally evaluated at several stages during the training, using competency benchmarks associated with quality delivery. Once they start supporting participants, therapists are provided group consultation by Compass-trained mentors, who have access to session recordings and transcripts from their assigned therapists. Regular group mentoring meetings provide opportunities for feedback and contribute to the maintenance of consistent delivery throughout the trials.
Finally, fidelity assessment is performed using a set of items that are individually essential and collectively unique to the therapist behaviors in the CPSM. In compliance with Good Clinical Practice standards and to avoid the risk of unblinding, fidelity assessment is performed by independent expert fidelity raters. This process is among the first attempts to measure therapist fidelity in psychedelic trials.
Conclusions
The CPSM was designed to support participant safety in clinical trials involving COMP360 psilocybin treatment and to address the requisite criteria for potential regulatory approval of this promising treatment modality. Compatible with most evidence-based psychotherapeutic approaches and based on clearly delineated elements, the CPSM is intended to serve as a baseline standard of care in this setting. It is not a standalone treatment for treatment-resistant depression or any other psychiatric condition. Future research on the facets of psychological support and/or psychotherapy that most optimally complement psilocybin treatment could inform new pathways toward improved, personalized, and accessible mental health care.