Psilocybin with ACT and the Accept-Connect-Embody model

1. Introduction

Version followed: two published trial manuals, read side by side: (A) Imperial College London, Psilocybin for Depression: The ACE Model Manual, Rosalind Watts, 1st edition, July 2021 (PsyArXiv preprint; describes the Psilodep trials) and (B) the Yale Manual for Psilocybin-Assisted Therapy of Depression (using ACT as a Therapeutic Frame), Guss, Krause, Sloshower and Wallace, version 4.2 (2019; posted as a PsyArXiv preprint in 2020). Where they differ, the version is named. The theory papers (Watts and Luoma 2020; Sloshower et al. 2020, both Journal of Contextual Behavioral Science 15) were seen only as abstracts. [source: ACE Manual; Yale Manual v4.2; JCBS abstracts]

What it is. These are not stand-alone psychotherapies. They are psychological-support frames for psilocybin trials that borrow the psychological flexibility model of Acceptance and Commitment Therapy (ACT) to structure preparation, conduct during the medicine session and integration. The ACE model (Accept, Connect, Embody) was developed by Rosalind Watts at Imperial College London from her qualitative study of patients in the open-label psilocybin trial for treatment-resistant depression. That study found two change processes: movement from disconnection to connection, and from emotional avoidance to acceptance. Watts and Luoma (2020) then mapped those themes onto ACT's six processes. An "acceptance triad" (defusion, present-moment focus, willingness) and a "connection triad" (self-as-context, values, committed action) are the result. The Yale group (Sloshower, Guss, Krause and colleagues, run at VA Connecticut) chose ACT as the overall frame for a small placebo-controlled trial in major depressive disorder. [source: Watts & Luoma 2020 abstract; ACE Manual; Sloshower et al. 2020 abstract; Sloshower et al. 2024]

How change is thought to happen. Both groups hold that depression is kept going by experiential avoidance, cognitive fusion, rumination and reason-giving. They propose that the psilocybin experience can loosen these patterns and give direct, felt contact with acceptance, present-moment awareness and connection. ACT-informed preparation primes the participant to open to whatever arises. ACT-informed integration then turns what was felt into values-based behaviour, so the gains last. The Yale manual warns against a passive "magic bullet" view and casts the participant as an active agent of change. [source: Yale Manual v4.2 §1; Sloshower et al. 2020 abstract; Watts & Luoma 2020 abstract]

Scope and legal status. Both manuals describe research protocols run under regulatory approval with medical teams. The ACE manual states it "should not be used as an instruction for studies or clinical trials". It describes what was done in Psilodep. As of the APPA/BrainFutures guidelines (August 2023), psilocybin was a US federal Schedule I substance and no psilocybin therapy was FDA-approved. [source: ACE Manual; APPA/BrainFutures 2023] Other jurisdictions are [uncertain: check the current regulator]. Psilocybin is understood to be a Schedule 1 controlled drug in the UK, usable only in licensed research. Australia is understood to have allowed authorised psychiatrists to prescribe it for treatment-resistant depression since mid-2023. Oregon (since 2023) and Colorado run state-licensed psilocybin service programmes outside the FDA medical model. This guide gives no information on doses, routes, schedules or how to obtain the substance. Medical monitoring is the responsibility of the medical staff and is not described technically. For the general psilocybin session frame (Johns Hopkins, NYU, Imperial) see guide 055. This tab covers what the ACT/ACE frame adds.

2. Framework

Both manuals use the standard three-part structure: preparation, medicine session(s), integration. The number and spacing of medicine sessions are set by each trial protocol and are not given here. [source: ACE Manual; Yale Manual v4.2; Sloshower et al. 2024]

Version A: Imperial ACE (Psilodep) sequence [source: ACE Manual]

Screening (several contacts). Enquiry database, telephone screen, clinician-rated depression rating, a video call with the main therapists, then an in-person visit. That visit includes a psychiatric screen, meeting both guides and a brief visit from the principal investigator. From the start, participants are told the experience is unpredictable.
Check-in call. Covers medication changes required by the protocol (handled by study doctors), three intention questions, meaningful objects to bring, music preferences and practical needs.
Preparation day. A shared lunch with both guides, then a preparation session of about three hours. It has four parts: catch-up and personal history; "session tips" (stance and practicalities); intention work; and a guided rehearsal including the P-ACE ocean-dive visualisation.
Medicine session day. The guides meditate together beforehand. Phones are locked away on arrival. A set, mostly non-directive playlist is used, with eyeshades and both guides present throughout.
Integration. Fixed integration sessions: (A) the morning after a medicine session, with both therapists; (B) a call about a week later; a further integration session the morning after any later medicine session; and a ceremonial closing session at the end. Up to three extra video calls are available, and there is a three-level support structure between sessions. Research follow-up comes later, including a six-month qualitative interview.

Version B: Yale ACT-frame sequence [source: Yale Manual v4.2 §5; Sloshower et al. 2024]

Screening and consent. Written trial information, time for questions, signed participant commitments (see 4.8).
Psychoeducation 1 (about 2 h). Rapport; plan of sessions; the participant's experience of depression and past treatments; expectations about psychedelics; identifying ACT-relevant patterns; what the experience may be like, including difficult experiences; boundaries and departure rules; eyeshade/headphone trial; touch consent; intention setting; body-awareness and breathing practice.
Psychoeducation 2 (about 2 h). Check-in; medication model versus active-participant model; how the depressed mind maintains itself (creative hopelessness, ski-slope metaphor, fusion, experiential avoidance, reason-giving, self-discrepancy, willingness versus desire); mindfulness practice.
Medicine session (full day). A therapist and a sitter are present throughout, with a supervising physician available. The participant goes home only after physician clearance and with a designated companion.
Debriefing 1 (1 h, next day). Open narrative review, ACT-themed listening, mental-status and safety check.
Debriefing 2 (1 h, about a week later). Review of lasting effects; values clarification.
In the trial, the psychotherapy came to eight sessions wrapped around a placebo session and an active session in fixed order. A preparation session preceded each medicine session, and two integration sessions followed each one. Two further integration sessions came after the primary outcome point to help sustain gains. The manual pages read were truncated after Psychoeducation 2. The content of later debriefings and follow-ups is therefore taken from the trial paper's summary only [uncertain].

Eligibility published by the Yale trial [source: Sloshower et al. 2024]

Inclusion: adults aged 18 to 65 with DSM-5 major depressive disorder in a current moderate-to-severe episode, and at least one failed adequate antidepressant trial. Protocol-required washout of antidepressants and antipsychotics was medically supervised.
Exclusion: a primary psychiatric diagnosis other than MDD; active substance use disorder; personal or family history of psychotic or bipolar disorder; significant or unstable medical or neurological disease; psilocybin exposure within the past year.

Criteria for moving between phases [source: both manuals; synthesis where marked]

Into preparation: eligibility confirmed by the medical and psychiatric team, consent signed, participant commitments agreed (Yale), medication changes completed under medical supervision.
Into the medicine session: both guides know the participant; an intention is formulated; touch preferences and signals are agreed; the rehearsal is done; suicidality is checked at check-in (Yale); the participant is able to restate the stance, for example Trust, Let go, Be Open. Testing that the participant can restate it is [synthesis].
Leaving the medicine session: medical clearance, a first narrative given, and a companion briefed on possible after-effects (Yale).
Through integration: mental-status and safety check at the end of every integration session, with escalation to the physician if needed (Yale). Integration moves from witnessing, to distilling lessons, to applying them (ACE funnel, 4.25). Moving on when the participant can name lessons in their own words is [synthesis].
Ending: closing session, review of goals, and referrals onward to community or integration groups or individual therapy (ACE).

3. Guiding principles

[source: ACE Manual unless marked Yale; ACT triad from Sloshower et al. 2024]

Psychological flexibility is the target (Yale; ACE). Every activity should increase openness to experience, present-moment awareness and values-driven action. Choose interventions by which of these is weakest.
Accept and Connect as two directions (ACE). Integration material is sorted into acceptance processes (let go, sense, feel) and connection processes (self, meaning, intention). In each moment, ask whether this calls for accepting or for connecting.
Trust, Let go, Be Open (TLO; ACE, also cited in Yale). This is the central instruction given to participants. Teach it in preparation, and return to it whenever the participant tightens up.
In and through (ACE). Painful material is approached, not avoided. Anxiety is read as a sign of being "warmer", meaning closer to something important. Coach moving toward the difficulty, never away from it.
It is your journey (ACE). The participant does not need to please or report to the guides. Remove any pressure to perform. Agree simple signals so the participant can decline contact.
Constant presence; "If they are engaged, do nothing" (ACE). Intervene only when the participant is disengaged, struggling or asks. Silence is the default.
Non-directive during the medicine session, more active outside it (Yale). During the medicine session, offer empathic, largely silent presence. In preparation and integration, teach and guide actively.
Model what you teach (Yale). Guides show curiosity, acceptance, unhurried pace and respect for boundaries. Your own flexibility under pressure is part of the intervention.
Active participant, not magic bullet (Yale). The medicine may reveal possibilities, but the participant must act on them. Frame every insight as a starting point for behaviour.
Workability over truth (Yale). Judge a thought by how much it gets in the way, not by whether it is true. Do not argue content; ask what following the thought costs.
Hold it lightly (ACE). Insights are not fixed facts. Discourage grand conclusions or major life decisions made on the strength of a single experience.
Stuckness is valid material (ACE). A blocked or "nothing happened" session is still data to collect and work with. Never treat it as failure.
Witness before interpreting (ACE). In the first integration contact, listen and help build the narrative, and offer no interpretations.
Consent is negotiated in advance and revocable (both). This covers touch, contact and boundaries. Nothing physical happens that was not agreed beforehand, and agreement can be withdrawn at any time.
Guides attend to themselves (both). Before sessions, share intentions, sensitive areas and countertransference with the co-guide. The Yale manual asks therapists to notice their own transferences and includes a therapist self-care appendix.
Safety over process (Yale). Participants agree in advance to follow therapists' safety advice. If a disagreement cannot be resolved, the clinical judgment of the team stands.

4. Intervention inventory

Order follows the treatment sequence. Each item names its source manual. All example language is illustrative unless it is in quotation marks with a citation. Neither manual's scripts are reproduced; they are paraphrased.

Preparation phase

4.1 Screening and eligibility assessment (both)

Purpose: Select participants for whom the protocol is safe, and begin the relationship.
Steps:
1. Take a structured history and confirm the diagnosis. Yale used a structured clinical interview and a clinician-rated depression scale. Imperial used a telephone screen, a depression rating and a psychiatric screen.
2. Ask about personal and family history of psychosis and bipolar disorder, substance use, medical and neurological illness, and recent psychedelic use. These are the published Yale exclusions.
3. Assess suicidality at intake. Yale repeats this at every check-in.
4. Route medication changes required by the protocol to the study physicians.
5. In ACE, the participant meets both guides before the preparation day (video call, then in person).
Example language (illustrative): "Some of these questions are about your family as well as you. A few conditions in relatives change whether this is safe for you."
Watch for: Minimising of manic or psychotic symptoms, or of substance use, by a participant keen to enrol. Corroborate with a collateral history or records where the protocol allows [synthesis].
[source: Sloshower et al. 2024; ACE Manual; Yale Manual v4.2 §4]

4.2 Informed consent and expectation-setting (both)

Purpose: Make consent real despite effects that are hard to describe in advance, and lower the pressure of high expectations.
Steps:
1. Give written trial information and unhurried time for questions (Yale).
2. State repeatedly that the experience is unpredictable (ACE).
3. Disclose the risks in plain terms. The APPA/BrainFutures guidelines list perceptual and emotional changes, possible psychosis, suicidality and persisting perceptual changes.
4. Treat consent as ongoing and revocable. Explain the one limit: after a medicine session starts, the participant stays on site until it is safe to leave.
Example language (illustrative): "People's sessions vary a great deal, and your two sessions may not be alike. If you go in expecting one particular thing, it can get in the way."
Watch for: Fixed expectations of cure. Address them with the canoe framing (4.12) and Hold it lightly (4.27).
[source: ACE Manual; Yale Manual v4.2 §4.1–4.2; APPA/BrainFutures 2023 Guideline 4]

4.3 Personal history and ACT pattern formulation (both)

Purpose: Build rapport and identify the avoidance, fusion and rumination patterns that integration will later target.
Steps:
1. Explore the participant's history and experience of depression and of past treatments (Yale Psychoeducation 1). In ACE, the history continues at the preparation-day catch-up.
2. Ask what the participant has done to escape or control painful states, and what it has cost them.
3. Note the main thoughts they are fused with, for example "I am a failure", and the values that depression has crowded out.
4. Invite anything not yet said (ACE catch-up).
Example language (illustrative): "When the low feeling comes, what do you usually do to get away from it? And in the long run, where has that taken you?"
Watch for: Whether the participant can see their coping as avoidance. That prepares the ground for creative hopelessness (4.5).
[source: Yale Manual v4.2 §5.1; ACE Manual]

4.4 Medication model versus active-participant model (Yale)

Purpose: Move the participant from passive recipient to active agent.
Steps:
1. Contrast the usual medication model (take a pill and wait) with the psychedelic-assisted model. In the latter, the substance may open possibilities, but the participant changes their thinking and action.
2. Link this to the intention (4.9).
Example language (illustrative): "The session may show you a door. Walking through it is the work we do together afterwards."
Watch for: The participant attributing all change to the substance. Return to this framing in integration.
[source: Yale Manual v4.2 §5.5]

4.5 Creative hopelessness (Yale)

Purpose: Help the participant see from experience that their usual strategies to control depression keep it going. This makes room for willingness.
Steps:
1. List with the participant the strategies they have used against low mood and painful thoughts.
2. For each, ask whether it worked in the short term and in the long term, and what it cost.
3. Reflect the pattern without blame: the struggle itself has become part of the problem.
4. Do not offer a fix yet. Let the hopelessness about control sit.
Example language (illustrative): "You've worked very hard at this. Looking at the list, does it seem that trying harder to get rid of these feelings has made them go away?"
Watch for: Hearing it as "I'm hopeless" rather than "the control agenda is hopeless". Name the difference explicitly [synthesis].
[source: Yale Manual v4.2 §5.5]

4.6 Ski-slope metaphor (Yale)

Purpose: Give a simple image of how psilocybin is thought to help and why integration matters.
Steps:
1. Describe depression as deep, well-worn ruts on a ski slope that thinking keeps sliding into.
2. Describe the psilocybin experience as like fresh snow covering the slope. This is a temporary chance to cut new tracks.
3. Explain that new tracks must be skied repeatedly to become the easy route. That repetition is the integration work.
Example language (illustrative): "After the session the old grooves are softer for a while. What we practise in those weeks is what sets in."
Watch for: The participant using the image to explain their own rumination later. That is a sign it has landed [synthesis].
[source: Yale Manual v4.2 §5.5]

4.7 ACT psychoeducation on the depressed mind (Yale)

Purpose: Teach the processes that integration will target, before the medicine session.
Steps: Cover each topic briefly with examples from the participant's own history (4.3):
1. Cognitive fusion: taking thoughts as literal truths.
2. Experiential avoidance.
3. Reason-giving and rumination.
4. Self-discrepancy: the gap between actual and ideal self.
5. Willingness versus desire: you can be willing to have a feeling without wanting it. Close with a mindfulness practice (4.17).
Example language (illustrative): "Notice the difference between 'I am worthless' and 'I'm having the thought that I'm worthless.' Same words, but a different relationship to them."
Watch for: Intellectual agreement without experiential contact. Use brief experiential exercises rather than more explanation [synthesis]. The manual pages read were truncated within this section, so the full list of exercises is [uncertain].
[source: Yale Manual v4.2 §5.5]

4.8 Participant commitments and boundaries (Yale; also ACE)

Purpose: Agree the safety frame before any altered state.
Steps:
1. Go through the agreements one by one and get explicit assent to each:
  - touch only as agreed, and never sexual;
  - remaining clothed;
  - no harm to self, others or property;
  - following safety advice;
  - staying in the treatment area until cleared;
  - telling staff about suicidal thoughts.
2. Explain that if a disagreement cannot be resolved during the session, the team's clinical judgment stands.
3. Confirm the right to withdraw from the study at any time.
Example language (illustrative): "These agreements are for the moments when your judgement may feel different from usual. Agreeing to them now is how you look after yourself then."
Watch for: Any reluctance about specific agreements. Explore it before proceeding.
[source: Yale Manual v4.2 §3.5, §4.3]

4.9 Intention setting (ACE; Yale)

Purpose: Orient the session and give integration a reference point.
Steps (ACE):
1. At the check-in call, ask three questions (paraphrased):
  - What would make the session meaningful whatever happens, and why are you doing it?
  - What would give you courage if it gets hard, such as a person, a value or a song?
  - What do you want more of in your life afterwards? Keep the answer realistic and focused on feelings.
2. Invite meaningful objects to bring.
3. On the preparation day, turn the hopes into one short, positively worded sentence.
Steps (Yale): Explain that a clear intention shapes the experience. Make the intention about changing the patterns of thinking and action that make up the participant's depression.
Example language (illustrative): "Can we turn 'I don't want to feel so dead inside' into something you're moving toward, in one sentence?"
Watch for: Intentions that are demands for an outcome, for example "I must be cured". Reframe them toward openness [synthesis, consistent with TLO].
[source: ACE Manual; Yale Manual v4.2 §5.1]

4.10 Session-tips briefing: Trust, Let go, Be Open (ACE)

Purpose: Install the core stance the participant will use during the session.
Steps:
1. Teach the mantra "Trust, Let go and Be Open" [source: ACE Manual]. The manual also expands the trust part as trusting the substance, one's own mind and the therapist.
2. Repeat that effects are unpredictable.
3. Give the safety information about the substance that the manual includes. That information is a matter for the medical team's consent process.
4. Introduce the other briefing elements: in and through (4.11), the canoe (4.12), it is your journey (4.13), and grounding (4.16).
5. Ask the participant to say the stance back in their own words [synthesis].
Example language (illustrative): "If you remember only one thing: trust, let go, be open. Whatever shows up, see if you can turn toward it."
Watch for: Treating TLO as a performance demand. Pair it with "it is your journey" (4.13).
[source: ACE Manual]

4.11 In and through; warmer/colder; the dragon (ACE)

Purpose: Turn fear and pain into signals to approach rather than avoid. This is the acceptance processes put to work in the session.
Steps:
1. Explain that, if difficult feelings come, the guidance is to go into and through them rather than away.
2. Use the warmer/colder image: rising anxiety may mean you are getting closer to something important.
3. Offer the image of a fiery dragon. If something frightening appears, the participant can ask it what it is there to teach.
4. Link this to the Yale guidance to "lean in" to intense feeling.
Example language (illustrative): "If you feel fear rising, see it as getting warmer. You could even ask it: what are you here to show me?"
Watch for: Participants who will take this as a mandate to override panic. In the session, pair it with grounding (4.16) and permission to sit up or remove the eyeshades (4.23).
[source: ACE Manual; Yale Manual v4.2 §5.2]

4.12 The canoe ride (ACE)

Purpose: Convey the roles: the participant steers and the guide is a constant companion.
Steps: Describe the session as a canoe journey through an inner forest. The participant navigates, and the guide is in the canoe the whole time. Return to this image in the session if the participant feels alone.
Example language (illustrative): "You choose where the canoe goes. I'm sitting behind you the whole way."
Watch for: Over-reliance on the guide to steer. Hand the paddle back gently [synthesis].
[source: ACE Manual]

4.13 "It is your journey": contact signals (ACE)

Purpose: Remove pressure to please or report, and protect autonomy.
Steps:
1. Tell the participant they do not need to talk or report.
2. Agree signals: thumbs-up for "I'm fine", a signal for "not now", and a way to ask for a tap on the shoulder.
3. Explain that toilet breaks, sitting up, walking about the room or looking at a book are all allowed.
Example language (illustrative): "If I check in and you don't want to talk, a thumbs-up is plenty. You don't owe me a report."
Watch for: Participants who are people-pleasers and narrate for the guides' benefit. Gently remind them of this agreement.
[source: ACE Manual]

4.14 Touch negotiation (both)

Purpose: Make supportive touch available without ambiguity, and protect against boundary violations.
Steps:
1. In preparation, discuss whether touch is wanted and which forms (both manuals): hand-holding, or a hand on the arm or shoulder.
2. Agree a signal to ask for touch, for example raising a hand, and a signal to withdraw from it.
3. Record the agreement and share it with the co-guide.
4. In the session, use only the forms agreed. If trauma-related material comes up, ask again before offering reassuring touch (ACE).
5. Sexual or erotic touch is prohibited (Yale; APPA/BrainFutures). APPA/BrainFutures separates touch the patient may refuse (comforting, reassuring, grounding) from touch that may be needed for safety (preventing harm).
Example language (illustrative): "Some people find it steadying to hold a hand. Others don't want any contact. Neither is better. What would you like, and how will you let me know if that changes?"
Watch for: Ambivalence about touch, or a history of abuse. Default to no touch, or to the participant initiating it [synthesis].
[source: ACE Manual; Yale Manual v4.2 §3.5; APPA/BrainFutures 2023 Guideline 5]

4.15 Preparing for projections, "heart opening", suspicion and sexual feelings (ACE; Yale)

Purpose: Normalise relational experiences in advance so they can be named rather than acted on or hidden.
Steps:
1. Tell the participant that they may feel strong warmth or love toward a guide ("heart opening"), suspicion or paranoia, or sexual feelings. Explain that these are normal and can be spoken about.
2. Agree that such feelings will be discussed openly, and that the boundaries (4.8) stay in place.
Example language (illustrative): "You might feel suspicious of us, or very close to us. Both happen. Saying it out loud helps; it doesn't offend anyone."
Watch for: Shame afterwards. Bring it up gently in integration [synthesis].
[source: ACE Manual; Yale Manual v4.2 §5.2]

4.16 Grounding and body practices: focusing, heart breathing, body sweeps (ACE); body-sensation awareness and abdominal breathing (Yale)

Purpose: Give the participant ways to stay present and move from thinking into sensation when overwhelmed or stuck. This is the "Sense" and "Feel" processes, and the closest the manuals come to "Embody".
Steps:
1. Focusing (ACE): find where an emotion is in the body, give it a word, and stay with it.
2. Heart breathing (ACE): breathe with attention resting in the chest or heart area.
3. Body sweep or scan (ACE): move attention slowly through the body.
4. Body-sensation awareness (Yale): bare attention to sensations without judgment.
5. Abdominal breathing (Yale): slow belly breathing.
6. Practise each in preparation so it is familiar before the session.
Example language (illustrative): "Where do you feel this right now? Put a hand there if that helps, and breathe toward it. You don't have to change it."
Watch for: Grounding used as avoidance. Use it to steady, then invite the participant back toward the material [synthesis].
[source: ACE Manual; Yale Manual v4.2 §5.1]

4.17 Mindfulness practice (Yale)

Purpose: Build present-moment awareness and acceptance as skills before the medicine session.
Steps: Lead a short mindfulness exercise in Psychoeducation 2. Debrief what the participant noticed, especially moments of struggling against an experience versus allowing it. Suggest home practice [synthesis].
Example language (illustrative): "Each time you notice your mind has wandered, that noticing is the practice. Gently come back."
Watch for: Distress in practice, such as trauma memories or dissociation. Shorten the practice, keep the eyes open, or focus outward [synthesis].
[source: Yale Manual v4.2 §5.5]. The specific script used is [uncertain] because the pages read were truncated.

4.18 Eyeshade and headphone rehearsal (both)

Purpose: Familiarise the participant with the session setting and lower anxiety on the day.
Steps: In the session room, the participant lies on the couch wearing the eyeshades and headphones and listens to music for a while. Practise the agreed signals (4.13, 4.14). Ask how it felt.
Example language (illustrative): "Let's try the eyeshades for a few minutes, so on the day it's already familiar."
Watch for: Claustrophobia or panic. Agree in advance that the eyeshades can come off at any time.
[source: ACE Manual; Yale Manual v4.2 §5.1]

4.19 P-ACE ocean-dive guided visualisation (ACE)

Purpose: Rehearse in imagination the Accept-Connect stance the participant will need in the session.
Steps:
1. With eyeshades on, guide an imagined dive. The diver swims down through currents and pushes through tangled weed.
2. On the sea floor the diver finds oyster shells, which stand for difficult emotions. Prising one open reveals a pearl, the lesson the emotion holds.
3. Then guide a return to the boat to reflect on the intention.
4. Debrief what the participant noticed. Use your own words; do not read the manual's script.
Example language (illustrative): "Imagine a shell that seems stuck shut. Stay with it, and see if it opens a little. What's inside?"
Watch for: Images of being unable to surface, or drowning fears. Offer a different image, such as walking into a forest, and process the fear [synthesis].
[source: ACE Manual; PIPS blog]

4.20 Music planning (both)

Purpose: Support the arc of the session without directing its content.
Steps:
1. Ask about the participant's music preferences at check-in (ACE).
2. Use a curated, mostly non-directive playlist. ACE includes participant-chosen tracks at the end. Yale used the same playlist for all sessions, including placebo.
3. Explain that the participant can ask to turn the music off (Yale) or to change it if it blocks them (ACE).
4. Keep softer tracks in reserve for moments of strong emotion (ACE).
Example language (illustrative): "If a piece of music feels wrong, tell us and we'll change it or turn it down."
Watch for: Music that triggers specific memories. Ask about pieces with strong personal associations in advance [synthesis].
[source: ACE Manual; Yale Manual v4.2 §3]

4.21 Therapist pre-session preparation (both)

Purpose: Prepare the dyad so their own states do not shape the session unexamined.
Steps (ACE):
1. The guides meet beforehand to share the participant's intentions, sensitive areas, and touch and music preferences.
2. They also share their own countertransference.
3. They do a short meditation together before the participant arrives, to establish the field.
4. They agree roles: one collects the participant and sets up the room.
Steps (Yale): Reflect on your own transferences and life circumstances, and follow the self-care guidance (Appendix A).
Example language (illustrative, between guides): "I'm aware I feel protective of her. I'll keep an eye on whether I'm stepping in too soon."
Watch for: Guide fatigue on long session days, and differences of approach between co-guides. Debrief these afterwards [synthesis].
[source: ACE Manual; Yale Manual v4.2 §3, Appendix A]

Medicine session phase

4.22 Constant presence: do nothing / do something (ACE; Yale non-directive stance)

Purpose: Hold safety and attention with as little intrusion as possible.
Steps:
1. Stay present and attentive throughout. Two staff are in the room at all times (ACE: two guides; Yale: a therapist and a sitter, with brief absences only, and a physician available).
2. ACE rule: "If they are engaged, do nothing." If the participant is not engaged, do something: check in, ask about resistance, offer agreed touch, guide breathing, ask what they are seeing, or encourage.
3. Yale: respond when the participant makes contact, and otherwise stay quiet.
4. Phones stay silent and are used only for emergencies.
5. Medical monitoring is carried out by the medical staff as the protocol requires.
Example language (illustrative): "I'm here." Or, if the participant seems to be pulling away from something: "Is there something you're holding back from? You can go toward it."
Watch for: The guide's urge to fill silence or to interpret. Ask whether an intervention serves the participant or relieves your own anxiety [synthesis].
[source: ACE Manual; Yale Manual v4.2 §5.2]

4.23 Responding to difficult experiences in session (both)

Purpose: Help the participant stay with and move through hard material, and know when to stabilise instead.
Steps, by situation:
- Intense emotion: gently encourage the participant to lean in (Yale), or to go in and through (ACE). Validate the feeling. ACE frames strong emotion as an opportunity.
- Struggling to let go, or a "bad trip" that seems driven by resistance (ACE): name the struggle and validate it. Change the music. Offer a body scan or a guided relaxation such as a stream visualisation. Return to TLO.
- Agitation (Yale): encourage breathing, sitting up, or taking the eyeshades off. Consider changing the music. Medical intervention is the physician's last resort.
- Paranoia or suspicion: stay calm. Reassure the participant that the state is temporary and that they are safe (Yale). Discuss it openly (ACE).
- Feeling of dying: reassure them of your presence ("I'll be with you", ACE).
- Urges to hit or push: offer a pillow and blanket as a contained outlet (ACE).
- Undressing: first ask the participant not to, then say so more firmly, referring to the prior agreement (Yale).
- Romantic or "heart opening" feelings toward a guide: acknowledge them warmly and keep the boundaries (4.15).
Example language (illustrative): "This is really hard, and you're doing it. Breathe with me. It will pass. You're safe here."
Watch for: Signs that need the physician: inability to be reassured, risk to self or others, or medical symptoms. Escalate rather than persisting with psychological strategies.
[source: ACE Manual; Yale Manual v4.2 §5.2]

4.24 Observation notes, first narrative and evening journaling (both)

Purpose: Capture the experience while it is fresh, without interrupting it.
Steps:
1. Guides write observations only when the participant is calm and "inside themselves" (ACE). The observation form has room for notes for supervision.
2. Near the end of the session, invite a first narrative focused on what happened rather than what it means (Yale).
3. Encourage unfiltered writing in the participant's own notebook that evening (ACE).
4. Before discharge: the physician clears the participant, and the companion is briefed on possible after-effects, such as headache, mood change, or rarely paranoia or suicidal thoughts. The participant knows how to reach staff (Yale).
5. Yale asked participants not to discuss their experience publicly until the study ended.
Example language (illustrative): "Just tell us what happened, in any order. We'll work out what it means later."
Watch for: Pressure to make immediate meaning or announce big decisions. Use Hold it lightly (4.27).
[source: ACE Manual; Yale Manual v4.2 §5.2]

Integration phase

4.25 The integration funnel (ACE)

Purpose: Pace integration so that meaning grows out of the experience rather than being imposed on it.
Steps:
1. Stage 1, witnessing: unstructured listening and building the narrative, with no interpretation.
2. Stage 2, distilling: draw out the lessons and link them to the participant's history.
3. Stage 3, applying: values, goals and relapse prevention (4.30, 4.31).
4. Move to the next stage only when the participant leads there. Using this as the move-on criterion is [synthesis].
Example language (illustrative): Stage 1: "Take me through it from the start." Stage 2: "Looking back, what do you think it was showing you?" Stage 3: "What would living that look like next week?"
Watch for: The therapist rushing to stage 3. Participants may also skip straight to grand lessons without the felt narrative.
[source: ACE Manual]

4.26 First integration session: the morning after (ACE Integration A; Yale Debriefing 1)

Purpose: Witness the experience, check safety, and set up support between sessions.
Steps:
1. With both guides (ACE), invite an open, full narrative. Ask specifically about difficult moments and how the participant has been since (Yale).
2. Listen for ACT themes without imposing them (Yale).
3. Explain the support available. ACE uses three levels: calls with an assistant psychologist, up to three extra video sessions with a therapist, and the study doctor or emergency services for urgent concerns, including suicidal thoughts.
4. Suggest journaling. Introduce the simple Accept/Connect "postcard", a one-page summary of the two directions (ACE).
5. End with a mental-status and safety check (Yale).
Example language (illustrative): "Before we finish, how is your mood right now, and have you had any thoughts of harming yourself since yesterday?"
Watch for: Distress after the session, disappointment, or confusion. Book the next contact before the participant leaves [synthesis].
[source: ACE Manual; Yale Manual v4.2 §5.3]

4.27 The ACE six-process integration map and Hold it lightly (ACE)

Purpose: Give a shared map for sorting integration material into Accept and Connect work.
Steps:
1. Introduce the six processes in plain language:
  - Accept: Let go (defusion), Sense (present moment), Feel (willingness).
  - Connect: Self (self-as-context), Meaning (values), Intention (committed action).
2. For each theme the participant raises, ask together whether it calls for accepting or for connecting, and how they might do that.
3. Use the kinds of questions the manual gives (paraphrased):
  - What was hard to accept, and what might I now be open to accepting?
  - Does any of my past look different now?
  - If new paths have opened, how will I notice whether I'm keeping to them?
4. ACE gives the simple postcard first and the full six-process diagram later, at the closing session.
5. Throughout, invite the participant to hold insights lightly, not as fixed facts.
Example language (illustrative): "Is this something to make room for, or something to move toward? Maybe both."
Watch for: The manual's appendix of example questions for every process is not drawn on. Questions for Let go, Sense, Meaning and Intention are therefore [uncertain]; write your own in ACT style.
[source: ACE Manual; Watts & Luoma 2020 abstract]

4.28 Defusion: thoughts are not facts; the workability question (Yale; ACE "Let go")

Purpose: Consolidate any loosening of rigid depressive thoughts that the session produced.
Steps:
1. Ask the participant to recall a thought that felt less gripping during or after the session.
2. Practise watching thoughts arise and pass.
3. When an old thought returns, ask how far it gets in the way of what matters, not whether it is true.
4. Link back to the ski-slope metaphor (4.6).
Example language (illustrative): "Your mind is offering 'nothing will change' again. If you follow that thought, where does it take you?"
Watch for: Arguing about whether the thought is true. That is a cue to return to workability.
[source: Yale Manual v4.2 §5.5; ACE Manual]

4.29 Self-as-context: the weather metaphor (Yale; ACE "Self")

Purpose: Strengthen the sense of a self that observes changing experience. Participants often report this in the session.
Steps:
1. Describe thoughts and feelings as weather, and the self that notices them as distinct from the weather.
2. Link this to any session experience of seeing oneself from a wider perspective.
3. ACE: explore whether the past looks different from this vantage point.
Example language (illustrative): "In the session you described watching your sadness without being swallowed by it. That watcher is still here."
Watch for: Spiritual or metaphysical interpretations of this experience. Respect them as the participant's own meaning, without endorsing or disputing them [synthesis].
[source: Yale Manual v4.2 §5.5; ACE Manual]

4.30 Values clarification (Yale Debriefing 2; ACE "Meaning")

Purpose: Turn the connection felt in the session into chosen directions.
Steps:
1. Use a values instrument. Yale used the Valued Living Questionnaire, a published values measure; its items are not reproduced here.
2. Discuss which values matter most and which have been lost to depression.
3. Ask which values were imposed by others rather than chosen.
4. Link the values to session content: who or what the participant felt connected to.
Example language (illustrative): "You said in the session you felt how much your brother matters. Where does that sit among your values, and how much has depression pushed it aside?"
Watch for: "Should" values that are really fear-driven. Explore them with the imposed-versus-chosen question.
[source: Yale Manual v4.2 §5.3; ACE Manual]

4.31 Committed action: gentle goals, a "journal of new things", barriers and setback plan (ACE Integration C/D; Yale)

Purpose: Embed the lessons in behaviour. This is the "Intention" process, and it matches the secondary-source description of "Embody" as values-driven action.
Steps:
1. Set around three specific, gentle goals for the coming weeks (ACE).
2. Optionally keep a "journal of new things" tried (ACE).
3. In later sessions, identify the barriers to the new behaviours and write a setback plan (ACE).
4. Yale: set goals that express the clarified values.
Example language (illustrative): "Let's pick three small things you could do in the next three weeks that come from what you learned. Small enough that you'd do them on a bad day."
Watch for: Goals that are too ambitious in the post-session glow. Plan in advance for the dip when the afterglow fades [synthesis].
[source: ACE Manual; Yale Manual v4.2 §1, §5; PIPS blog on Embody]

4.32 Journaling prompts between sessions (ACE)

Purpose: Continue processing between contacts.
Steps: Encourage unfiltered writing first. Then offer prompts organised by acceptance (what am I making room for?) and connection (what am I moving toward?). Paraphrase these; ACE's own prompts are not reproduced.
Example language (illustrative): "Write whatever comes, without editing. If you get stuck, try: what did I stop fighting this week?"
Watch for: Journaling that becomes rumination. Narrow the prompt to a single question [synthesis].
[source: ACE Manual]

4.33 Closing session (ACE Integration D) and extended follow-up (Yale)

Purpose: End the therapeutic relationship well and hand on support.
Steps:
1. Hold a ceremonial closing. Review progress against goals and the intention.
2. Complete trial procedures such as unblinding, and plan onward clinical care with the study doctors.
3. Give participants the full six-process diagram where relevant.
4. Provide resources and referrals: community and integration groups, individual integration therapy, and the GP for medical follow-up.
5. Yale added extra integration sessions after the primary outcome point to help sustain gains.
Example language (illustrative): "Let's look back at the sentence you wrote before your first session. What has happened to it?"
Watch for: Loss reactions at ending, or a return of symptoms. Make sure there is a named route back to care.
[source: ACE Manual; Sloshower et al. 2024]

4.34 Tracking the ACT processes (Yale trial)

Purpose: Monitor whether the targeted processes are changing.
Steps: The Yale trial measured four things at baseline and at intervals afterwards:
- psychological flexibility (Acceptance and Action Questionnaire-II);
- mindfulness skills (Kentucky Inventory of Mindfulness Skills);
- valued living (Valued Living Questionnaire);
- self-reported depression (QIDS-SR-16). Use published measures under their own terms of use; no items are reproduced here. Bringing the scores into integration sessions is [synthesis].
Watch for: Flexibility scores improving while mood lags, or the reverse. Discuss either with the participant [synthesis].
[source: Sloshower et al. 2024]

4.35 Adapting the frame for clients who use psilocybin outside legal programmes [synthesis]

Purpose: Neither manual covers this. Many clinicians meet clients before or after use outside legal settings. The clinician's role is harm reduction and integration, never facilitation.
Steps:
1. Assess using the trial exclusions as a risk guide: personal or family history of psychosis or bipolar disorder, active substance use disorder, significant medical or neurological illness, and current suicidality.
2. Explain in general terms that interactions with prescribed psychiatric and other medications are a real risk and need review by the prescriber. Give no dosing or sourcing information.
3. Draw up a safety plan with crisis contacts.
4. Refer to legal or regulated programmes where they exist.
5. Afterwards, use the integration tools (4.25 to 4.33) to process what happened.
6. Document that you neither recommended nor arranged use.
Example language (illustrative): "I can't help you get or take it. I can help you think through the risks for you specifically, and I can help you make sense of whatever happens."
Watch for: Mania, psychosis, persisting perceptual changes or increased suicidality afterwards. Arrange urgent psychiatric assessment.
[synthesis; consistent with APPA/BrainFutures 2023 Guideline 11 on integration]

5. Handling problems

Each item is tagged by source; untagged steps inside a [synthesis] item are the author's guidance.

Stuck session, or "nothing happened" (ACE).
- In ACE, stuckness is valid material, and the task is to collect experiences and keep moving forward where possible.
- In session: check in, ask about resistance, change the music, offer focusing or a body scan, and return to TLO (4.22, 4.23).
- In integration: treat the stuckness as information. Ask what it was like to want something and not get it, and what that mirrors in their life. Linking it to the participant's control agenda (4.5) is [synthesis].
Resistance and the "bad trip" (ACE; Yale).
- ACE notes that bad trips are often linked to resistance. Validate the struggle rather than fighting it, then invite going in and through (4.11).
- Yale: encourage leaning into intense affect, while normalising fear and confusion.
- Use grounding first if the participant cannot hear the invitation, and only then invite them in. That ordering is [synthesis].
Overwhelm, agitation or panic (Yale; ACE).
- Encourage slow breathing and sitting up, take off the eyeshades, change the music, and use the agreed touch.
- Keep reassurance simple: the state is temporary and they are safe.
- Medical intervention is the physician's decision and a last resort (Yale).
- Never leave the participant alone; two staff stay in the room (both manuals).
Paranoia or suspicion of the guides (Yale; ACE).
- Stay calm and transparent, and do not argue. Name that suspicion was anticipated in preparation (4.15).
- Afterwards, explore it openly as material. ACE treats projections as part of the process.
Fear of dying or of losing oneself (ACE). Reassure them of your presence ("I'll be with you"). Return to the canoe image and the intention. The idea of offering the intention as an anchor is [synthesis].
Urges to hit, push or leave (ACE; Yale).
- ACE offers a pillow and blanket as a contained outlet.
- Yale participants agreed to stay in the treatment area until cleared. Restate the agreement calmly, and involve the physician if the risk rises.
Breaking agreements in session, such as undressing or refusing safety advice (Yale).
- Ask once gently, then more firmly, citing the prior agreement.
- Where a disagreement cannot be resolved, the team's clinical judgment stands, as the participant agreed in advance.
- Write it up and debrief non-shamingly in integration. The debrief is [synthesis].
Romantic, sexual or idealising feelings toward a guide (ACE; Yale).
- Name and normalise the feelings, which were anticipated in preparation, and keep every boundary. Sexual touch is prohibited (Yale; APPA/BrainFutures).
- Discuss in supervision. ACE observation forms have space for supervision notes.
- Afterwards, the same rule applies to former patients and anyone under your authority (APPA/BrainFutures).
Ruptures [synthesis].
- Examples: a guide intervenes when the participant wanted silence, touch feels wrong, a co-guide disagreement is sensed, or the guides are blamed for a hard session.
- Ask about the rupture directly in the next integration session, take responsibility for your part, and re-agree the signals.
- If the participant's trust in one guide is damaged, involve the co-guide.
- None of this is found in the manuals read.
Trauma material surfacing (ACE, partly [synthesis]).
- ACE asks the guide to re-negotiate reassuring touch when trauma-related experiences arise.
- In integration, slow the funnel and stay at witnessing longer. Assess for intrusive symptoms, and refer to trauma-focused care if new memories or post-traumatic symptoms persist [synthesis].
- Do not validate or dispute the historical accuracy of memories that emerge [synthesis].
Disappointment after a session, including a placebo session in a blinded design (ACE Integration B checks disappointment; Yale design).
- Validate the disappointment and normalise variable sessions. Work with the disappointment through willingness (4.7) and the control agenda.
- Under blinding, do not speculate about what was given [synthesis]. The Yale manual pages read do not cover how to handle a participant's disappointment after placebo [uncertain].
Post-session deterioration or suicidal thoughts (Yale; ACE).
- Follow the escalation pathways set up beforehand. Yale: the study physician, and a companion briefed on rare after-effects. ACE: three levels of support, up to emergency services.
- Do a structured suicide risk assessment and safety plan, and agree lethal-means counselling (storage and removal) per current standard practice. These two are [synthesis, standard care].
Persisting perceptual changes, mania or psychotic symptoms after the session [synthesis]. These are named among the risks to disclose (APPA/BrainFutures). Refer promptly for psychiatric assessment, and record and report them as adverse events through the study's procedures.
Grandiose insight, or urges to make major life decisions (ACE Hold it lightly; [synthesis] for the decisions advice).
- Invite the participant to hold insights lightly.
- Suggest delaying irreversible decisions and testing insights through small committed actions (4.31) first.
Insight without change, or "the magic will do it" (Yale). Return to the active-participant model (4.4) and the ski-slope metaphor (4.6). Set small, concrete goals linked to values, and review the barriers (4.31).
Non-adherence to journaling, goals or integration contacts [synthesis].
- Treat it with curiosity, as possible avoidance, using workability.
- Shrink the goals, and use the setback plan (ACE).
- Offer the extra integration contacts ACE makes available.
Spiritual or metaphysical interpretations [synthesis].
- Accept them as the participant's meaning without endorsing or disputing their truth. Work with how the meaning guides values and action.
- Referring to the participant's own tradition, community or an integration group (ACE refers to community groups) is an option.
Therapist pitfalls [synthesis, informed by Yale's modelling principle].
- Over-interpreting, imposing ACT vocabulary in place of the participant's words, rushing to goals, and filling silence in session.
- Check: am I modelling flexibility, or managing my own discomfort?
Wish to repeat the experience outside the trial [synthesis]. Do not facilitate it. Use harm-reduction assessment (4.35), and explore what the participant hopes it would give them that integration work could pursue.

For general psilocybin-session problems (Hopkins/NYU/Imperial frames, medical adverse events) see guide 055.

Sources

Sources:

Psilocybin for Depression: The ACE Model Manual (Watts, 2021), Academia.edu copy of the PsyArXiv preprint. Preprint announced on PsyArXiv on 5 July 2021 (see Psychedelic Science Updates notice). The appendices could not be read.
Yale Manual for Psilocybin-Assisted Therapy of Depression v4.2 (Guss, Krause, Sloshower, Wallace). This is a copy hosted by a Polish ACT association site. The same manual was released by its authors as a PsyArXiv preprint; that record page loaded without content. Text was available only up to Psychoeducation 2 [uncertain beyond that point].
Watts & Luoma 2020, The use of the psychological flexibility model to support psychedelic assisted therapy, ACBS listing (abstract)
Sloshower et al. 2020, Psilocybin-assisted therapy of MDD using ACT as a therapeutic frame, ACBS listing (abstract)
Sloshower et al. 2024, Psychological flexibility as a mechanism of change in psilocybin-assisted therapy for major depression, Scientific Reports
APPA & BrainFutures, Professional Practice Guidelines for Psychedelic-Assisted Therapy, August 2023
PIPS Institute, Psychological Flexibility Model: Enhancing Psychedelic-Assisted Therapy (blog, secondary)