Anxiety DisordersMajor Depressive Disorder (MDD)Treatment-Resistant Depression (TRD)Depressive DisordersPsilocybin

The use of the psychological flexibility model to support psychedelic assisted therapy

This theory-building paper (2020) presents the ACE (Accept, Connect, Embody) model and how it's being used in a trial (Psilodep 2) with psilocybin-assisted therapy for depression.

Authors

  • Rosalind Watts
  • Jason Luoma

Published

Journal of Contextual Behavioral Science
individual Study

Abstract

Psychedelic assisted therapy comprises three stages: Preparation, Psychedelic Session, and Integration. Preparation is key for maximising the potential of a beneficial psychedelic experience and integration is important for prolonging improvements. The psychological flexibility model (PFM) appears to be a promising one to guide psychedelic preparation and integration. This paper proposes a model that utilises the PFM as informed by a previously published qualitative study of patient accounts of change processes in psilocybin therapy that identified themes of acceptance and connection as associated with positive outcomes. This new model, the ACE (Accept, Connect, Embody) model presents the six psychological flexibility processes, renamed and rearranged in an acceptance triad (defusion, present moment focus, willingness) and a connection triad (self as context, values, committed action). This paper describes the ACE model and how it is being used in an ongoing trial of psilocybin treatment for major depression. It also describes qualitative evidence supportive of the idea that psychological flexibility may be key to characterizing the processes of change involved in psilocybin assisted therapy for depression. These and other results suggest that psilocybin may be specifically increasing psychological flexibility and point to the possibility that psychotherapy approaches incorporating the PFM may serve as a means to deepen and extend the benefits of psilocybin treatment, thus bridging the experiential gap between a potent inner experience and an outer life better lived.

Available with Blossom Pro

Research Summary of 'The use of the psychological flexibility model to support psychedelic assisted therapy'

Introduction

Psychedelic assisted therapy typically comprises three stages—preparation, the psychedelic session itself, and integration—and effective non-drug psychotherapy around the session is considered crucial for safety and for prolonging benefits. Watts and colleagues note that, despite this consensus, specific and testable psychotherapeutic models to guide preparation and integration are sparse. They draw on findings from Psilodep 1, an open-label trial of psilocybin for treatment-resistant depression, and on broader clinical experience to argue that the psychological flexibility model (PFM) is a promising organising framework for this work. This paper introduces the Accept, Connect, Embody (ACE) model, an adaptation of the PFM tailored to psychedelic-assisted therapy. The ACE model reorganises the six PFM processes into an acceptance triad and a connection triad, and places embodiment as a pervasive element. Watts and colleagues set out to describe the ACE model, show how qualitative data from Psilodep 1 converge with PFM processes, and explain how the model is being implemented in an ongoing randomised, double-blind trial (Psilodep 2) to guide preparation and integration.

Expert Research Summaries

Go Pro to access AI-powered section-by-section summaries, editorial takes, and the full research toolkit.

Study Details

References (9)

Papers cited by this study that are also in Blossom

The Challenging Experience Questionnaire: Characterization of challenging experiences with psilocybin mushrooms

Barrett, F. S., Bradstreet, M. P., Leoutsakos, J. M. S. et al. · Journal of Psychopharmacology (2016)

Patient Experiences of Psilocybin-Assisted Psychotherapy: An Interpretative Phenomenological Analysis

Belser, A. B., Agin-Liebes, G. I., Swift, T. C. et al. · Journal of Humanistic Psychology (2017)

The entropic brain - revisited

Carhart-Harris, R. L. · Neuropharmacology (2018)

Psychedelics and the essential importance of context

Carhart-Harris, R. L., Roseman, L., Haijen, E. C. H. M. et al. · Journal of Psychopharmacology (2018)

Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness

Maclean, K. A., Johnson, M. W., Griffiths, R. R. · Journal of Psychopharmacology (2011)

Psychedelic therapy for smoking cessation: Qualitative analysis of participant accounts

Noorani, T., Garcia-Romeu, A., Swift, T. C. et al. · Journal of Psychopharmacology (2018)

Psychedelic Psychotherapy Insights From 25 Years of Research

Richards, W. A. · Journal of Humanistic Psychology (2016)

Patients’ accounts of increased “Connectedness” and “Acceptance” after psilocybin for treatment-resistant depression

Watts, R., Day, C. M., Krzanowski, J. et al. · Journal of Humanistic Psychology (2017)

Cited By (78)

Papers in Blossom that reference this study

Synergies in psychedelic-assisted therapy: a qualitative interview study of psychotherapeutic processes

Stellmacher, J., Schmidt, C., Aicher, H. D. et al. · Frontiers in Psychiatry (2026)

The combination of exercise and psychedelics for the treatment of major depressive disorder

Fabiano, N., Stubbs, B., Lawrence, D. W. et al. · Discover Mental Health (2026)

Reduced Brain Responsiveness to Emotional Stimuli With Escitalopram But Not Psilocybin Therapy for Depression

Wall, M. B., Demetriou, L., Giribaldi, B. et al. · American Journal of Psychiatry (2025)

From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS)

Zeifman, R. J., Spriggs, M. J., Kettner, H. et al. · Scientific Reports (2025)

24 cited
Psilocybin Therapy for Clinicians With Symptoms of Depression From Frontline Care During the COVID-19 Pandemic

Back, A., Freeman-Young, T. K., Morgan, L. et al. · JAMA Network Open (2024)

18 cited
6 cited
Show all 78 papers
Psychedelic-assisted psychotherapy: Where is the psychotherapy research?

Aday, J. S., Horton, D. M., Fernandes-Osterhold, G. et al. · Psychopharmacology (2024)

Unique Psychological Mechanisms Underlying Psilocybin Therapy Versus Escitalopram Treatment in the Treatment of Major Depressive Disorder

Weiss, B., Leor Roseman, •., Giribaldi, B. et al. · International Journal of Mental Health and Addiction (2024)

The ego in psychedelic drug action - ego defenses, ego boundaries, and the therapeutic role of regression

Buchborn, T., Kettner, H., Kartner, L. et al. · Frontiers in Neuroscience (2023)

Neuroimaging in psychedelic drug development: Past, present, and future

Wall, M. B., Harding, R., Zafar, R. et al. · Molecular Psychiatry (2023)

How does psilocybin therapy work? An exploration of experiential avoidance as a putative mechanism of change

Zeifman, R. J., Wagner, A. C., Monson, C. M. et al. · Journal of Affective Disorders (2023)

47 cited
The Relationship Between Naturalistic Psychedelic Use and Clinical Care in Canada

Glynos, N., Kruger, D. J., Kolbman, N. et al. · Journal of Psychoactive Drugs (2023)

9 cited
Must Psilocybin Always “Assist Psychotherapy”?

Goodwin, G. M., Malievskaia, E., Fonzo, G. A. et al. · American Journal of Psychiatry (2023)

Personality change in a trial of psilocybin therapy v. escitalopram treatment for depression

Weiss, B., Ginige, I., Shannon, L. et al. · Psychological Medicine (2023)

Dosing and Therapeutic Conduct in Administration Sessions in Substance-Assisted Psychotherapy: A Systematized Review

Thal, S. B., Wieberneit, M., Sharbanee, J. M. et al. · Journal of Humanistic Psychology (2023)

4 cited
Therapeutic effect of psilocybin in addiction: A systematic review

van der Meer, P. B., Fuentes, J. J., Kaptein, A. A. et al. · Frontiers in Psychiatry (2023)

Effective connectivity of functionally anticorrelated networks under LSD

Stoliker, D., Novelli, L., Vollenweider, F. X. et al. · Biological Psychiatry (2023)

23 cited
Psychedelic therapy for depressive symptoms: A systematic review and meta-analysis

Kopra, E., Cleare, A. J., Rucker, J. et al. · Journal of Affective Disorders (2022)

Being no one, being One: The role of ego-dissolution and connectedness in the therapeutic effects of psychedelic experience

Kałużna, A., Schlosser, M., Gulliksen Craste, E. et al. · Journal of Psychedelic Studies (2022)

35 cited
Effects of psilocybin versus escitalopram on rumination and thought suppression in depression

Barba, T., Buehler, S., Kettner, H. et al. · BJPsych Open (2022)

Pharmacological, Neural, and Psychological Mechanisms underlying Psychedelics: A Critical Review

van Elk, M., Yaden, D. B. · Neuroscience and Biobehavioral Reviews (2022)

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Hipólito, I., Mago, J., Rosas, F. E. et al. · Psyarxiv (2022)

Psychedelics, Mystical Experience, and Therapeutic Efficacy: A Systematic Review

Knight, G., Rucker, J., Cleare, A. J. et al. · Frontiers in Psychiatry (2022)

Postpartum depression: A role for psychedelics?

Jairaj, C., Rucker, J. · Journal of Psychopharmacology (2022)

Psychedelics and Psychotherapy: Cognitive-Behavioral Approaches as Default

Yaden, D. B., Earp, D., Graziosi, M. et al. · Frontiers in Psychology (2022)

Therapeutic Alliance and Rapport Modulate Responses to Psilocybin Assisted Therapy for Depression

Murphy, R., Murphy-Beiner, A., Kettner, H. et al. · Frontiers in Pharmacology (2022)

162 cited
Psilocybin-Assisted Compassion Focused Therapy for Depression

Pots, W., Chakhssi, F. · Frontiers in Psychology (2022)

Predictors and potentiators of psychedelic-occasioned mystical experiences

Gandy, S. · Journal of Psychedelic Studies (2022)

Virtual Reality as a Moderator of Psychedelic-Assisted Psychotherapy

Sekula, A. D., Downey, L., Puspanathan, P. · Frontiers in Psychology (2022)

19 cited
Exploring the Credibility of Psilocybin-assisted Therapy and Cognitive-behavioral Therapy for Depression

Altman, B. R., Earleywine, M., De Leo, J. · Journal of Psychoactive Drugs (2022)

4 cited
Psychedelic-Assisted Therapy for Substance Use Disorders and Potential Mechanisms of Action

Rieser, N. M., Herdener, M. ;., Preller, K. H. · Current Topics in Behavioral Neurosciences (2021)

Sub-acute and long-term effects of ayahuasca on mental health and well-being in healthy ceremony attendants: A replication study

van Oorsouw, K., Uthaug, M. V., Mason, N. L. et al. · Journal of Psychedelic Studies (2021)

17 cited
Novel Treatment Approaches for Substance Use Disorders: Therapeutic Use of Psychedelics and the Role of Psychotherapy

Johnson, M. W., Gründer, G., Betzler, F. et al. · Current Addiction Reports (2021)

Prefrontal contributions to the stability and variability of thought and conscious experience

Zamani, A., Carhart-Harris, R. L., Christoff, K. · Neuropsychopharmacology (2021)

Does psychedelic therapy have a transdiagnostic action and prophylactic potential?

Kočárová, C., Horacek, J., Carhart-Harris, R. L. · Frontiers in Psychiatry (2021)

73 cited
Psilocybin as a Novel Pharmacotherapy for Treatment-Refractory Anorexia Nervosa

Rodan, S., Aouad, P., McGregor, I. S. et al. · OBM Neurobiology (2021)

Psychedelics and health behaviour change

Teixeira, P. J., Johnson, M. W., Timmermann, C. et al. · Journal of Psychopharmacology (2021)

Future Directions for Clinical Psilocybin Research: The Relaxed Symptom Network

Lewis-Healey, E., Laukkonen, R., Van Elk, M. · Psyarxiv (2021)

1 cited
Set and Setting in the Santo Daime

Hartogsohn, I. · Frontiers in Pharmacology (2021)

Ethical and legal issues in psychedelic harm reduction and integration therapy

Pilecki, B., Luoma, J. B., Bathje, G. J. et al. · Harm Reduction Journal (2021)

A qualitative and quantitative account of patient’s experiences of ketamine and its antidepressant properties

Sumner, R. L., Chacko, E., Mcmillan, R. et al. · Journal of Psychopharmacology (2021)

51 cited
Naturalistic Use of Mescaline Is Associated with Self-Reported Psychiatric Improvements and Enduring Positive Life Changes

Agin-Liebes, G. I., Lancelotta, R., Uthaug, M. V. et al. · ACS Pharmacology and Translational Science (2021)

Psychedelic Harm Reduction and Integration: A Transtheoretical Model for Clinical Practice

Palhano-Fontes, F., Gorman, I., Nielson, E. M. et al. · Frontiers in Psychology (2021)

Acute Psychological Adverse Reactions in First-Time Ritual Ayahuasca Users

Gómez-Sousa, M., Jiménez-Garrido, D. F., Ona, G. et al. · Journal of Clinical Psychopharmacology (2021)

18 cited
51 cited
Psychedelics and Psychotherapy

Nayak, S., Johnson, M. W. · Pharmacopsychiatry (2020)

The History of Psychedelics in Psychiatry

Nichols, D. E., Walter, H. · Pharmacopsychiatry (2020)

The potential synergistic effects between psychedelic administration and nature contact for the improvement of mental health

Gandy, S., Forstmann, M., Carhart-Harris, R. L. et al. · Health Psychology Open (2020)

Pivotal Mental States

Brouwer, A., Carhart-Harris, R. L. · Journal of Psychopharmacology (2020)

82 cited
Integrating psychotherapy and psychopharmacology: psychedelic-assisted psychotherapy and other combined treatments

Greenway, K. T., Garel, N., Jerome, L. et al. · Expert Review of Clinical Pharmacology (2020)

Learning to Let Go: A Cognitive-Behavioral Model of How Psychedelic Therapy Promotes Acceptance

Wolff, M., Evens, R., Mertens, L. J. et al. · Frontiers in Psychiatry (2020)

292 cited
Toward a contextual psychedelic-assisted therapy: Perspectives from Acceptance and Commitment Therapy and contextual behavioral science

Luoma, J. B., Sabucedo, P., Eriksson, J. et al. · Journal of Contextual Behavioral Science (2019)

Your Personal Research Library

Go Pro to save papers, add notes, rate studies, and organize your research into custom shelves.