Psychological Flexibility and Psychedelic Therapy

This was originally published on EntheoNation.

It’s been said in a number of different ways, perhaps for as long as psychedelics have been around: psychedelics make you more flexible.

Flexibility can mean different things. It could mean the personality trait of openness– a behavioral flexibility to new experiences and concepts – which has been shown to be increased after psychedelic trips…[1] It could mean the increase of entropy, or disorder, seen in your brain while taking a psychedelic…[2] Or it could mean the change towards more tolerant viewpoints that psychedelics are likely to induce.[3]

In the language of psychologists and therapists, psychedelics can help us foster something called psychological flexibility. And this may be a crucial reason for why psychedelic-assisted therapy can be so powerfully transformative.

What is Psychological Flexibility?

Psychological flexibility is a set of behaviors and attitudes that can help people cope with the various struggles of life, or with specific past traumas. The characteristics that define psychological flexibility often describe adaptive, content and self-aware people.

The basic tenets of psychological flexibility are detailed in the psychological flexibility model (PFM), which lays out six flexibility processes:

  1. Being present in the moment. Not getting lost in rumination about the past, or worries about the future.
  2. Acceptance of unwanted feelings. Instead of avoiding or fighting the discomfort of negative emotions, learning to accept their presence.
  3. Cognitive defusion. Seeing your thoughts and cognitions as lenses through which you see the world, rather than being inherently true.
  4. The fluid nature of self. Learning that it’s impossible to fully define the limits and characteristics of the self, and accepting its dynamic nature.
  5. Meaningful values. Being able to clarify what a rich and fulfilled life would look like for you.
  6. Conscious action. Working towards a version of yourself that is consistent with your values.

Practicing and embodying these six processes gives people more tools to handle negative emotions, traumatic experiences, and spiritual crises. Even more than that, it can help people form healthier relationships and have more fulfilling lives.

Increases in psychological flexibility during therapy are associated with decreases in anxiety and depression,[4][5] and it has been theorized that depression and anxiety could be partly caused by reduced psychological flexibility.[6]

Some of the most successful and popular forms of therapy, such as Acceptance and Commitment Therapy (ACT), attempt to help people foster psychological flexibility, using the six processes above. So it’s no surprise that psychedelics, with their perspective-shifting capacity, have been investigated by psychedelic therapists as a tool to amplify psychological flexibility.

Research carried out at Johns Hopkins supports the idea that psychological flexibility could be part of the therapeutic value of psychedelics. They surveyed nearly a thousand psychedelic users, and found that the people who saw decreases in depression or anxiety after their psychedelic experiences were more likely to show increases in measures of psychological flexibility.[7]

This research shows that psychological flexibility can be increased by psychedelics, even in people who aren’t within a therapeutic context. This means that psychedelic-assisted therapy focussed on boosting psychological flexibility could optimize the healing benefits of psychedelics.

The ACE Model and Psychological Flexibility in Psychedelic Therapy

Dr Rosalind Watts at Imperial College London has developed a new model of psychedelic-assisted therapy, based on the psychological flexibility model. She calls it the “ACE” model – standing for “Accept Connect Embody” – and its aim is to boost psychological flexibility in people who are taking a psychedelic in the presence of a trained psychedelic guide or therapist.[8]

The ACE model is designed to adapt to the fact that psychedelics can bring up intense negative and positive emotions, that are often more extreme than those elicited in therapy alone. The basic idea is that when a patient encounters an intense negative emotion or process, the ACE model encourages them to first accept the negative feelings, then work towards connecting to the positive aspects that can be learned from challenging experiences, while constantly embodying themselves in the feelings and paying attention to where emotions are felt in the body.

An important part of the ACE model is reframing negative emotions as something to be engaged with, allowing for radical change and learning. Worry and rumination are often avoidance mechanisms, and changing the way we relate to them can allow healing emotional processing.

The ACE model can also help to maximize the benefits of positive feelings that psychedelics may elicit, by fostering a sense of connection with the world and a sense of the divine.

The Basic Principles of the ACE Model

The ACE model is highly flexible, allowing patients to lead their own journeys while being carefully followed and supported by the therapist. While the ACE model doesn’t attempt to enforce a strict path on the patient, its basic principles can be described like this:

Patients are encouraged to visualize themselves swimming through the dark, deep ocean, which represents their negative experience. Here, the patient is asked to accept the moment-to-moment painful experience and be fully present to it.

At the very darkest place in this experience the patient will come across some very ugly, spiky-looking clams. These represent the fear associated with the learning that can be gained from revealing your darkest shadows to yourself. However, when the patient is encouraged to open one of the clams, a beautiful bright pearl is revealed; representing a gift of positive meaning that can be brought into life.

The patient is ultimately encouraged to swim to the surface with their newfound treasure, where the pink sky represents positive emotion, and a connection to meaning and personal values that make life worth living. Throughout this process, the patient is reminded to be sensing and feeling everything in the body, in addition to thinking and talking about it.

The 50/50 split of the image highlights a core concept of the ACE model, which is that negative emotions (represented by the ocean) are equally as important as positive emotions (represented by the sky). In the words of Dr Watts, “If you hurt, you care and you hope.” Pain can produce healing, and these are two sides of the same coin.

How the ACE Model is Used in Psychedelic Therapy

During psychedelic-assisted therapy, the ACE model is introduced to the patient in the weeks before the psychedelic session, allowing the therapist to guide them through these visualization exercises that helps them get used to working through negative feelings while being able to take positives from them and stay connected to their body.

Once the patient has undergone this journey several times in preparation sessions, it can be easier for them to encounter their negative feelings during the psychedelic session itself. Ideally, at this point the therapist will purely be a guide, helping the patient come to their own insights and revelations. This “non-directive” principle is important during the psychedelic session, where the therapist must avoid imprinting any of their own biases and cognitions on the participant.

Integration following the psychedelic session also uses the ACE model, allowing the patient to revisit the negative experiences and reframe them in terms of positives. At later stages, the therapist may guide the patient towards finding new goals to carry forward into their lives.

Throughout the ACE process, patients are encouraged to foster the basic principles of psychological flexibility; especially acceptance, contact with the present moment, and reducing attachments to the concept of the self and to certain thought patterns.

Disclaimer! Dr Rosalind Watts and her colleagues are currently using the ACE model in their second trial of psilocybin therapy for severe depression, and it has not been quantitatively tested or compared to other methods of psychedelic-assisted therapy.

Don’t Try This At Home (But Learn From It)

There are truly fascinating things we can learn from the ACE model and the psychological flexibility model! They can help us understand what makes psychedelics so powerful, and how we can support people who are undergoing their own journeys.

However, it’s important to remember that the ACE model is a lot more complex than it may seem on the surface, and is designed for professional therapists to use. It’s also not been fully tested yet!

Although you may feel like you’re equipped to guide people through their healing journeys, be aware of your limitations. Remember that even professional therapists take a hands-off approach during psychedelic sessions, listening to and supporting their participants rather than forcing them to adhere to any strict guidelines or narratives.

The take-home message for us is that psychedelics can help us reach insights and states of mind that we ordinarily find it hard to reach. The ideal set and setting for a psychedelic trip is one in which we are empowered to explore these insights in depth, while always being safe and supported by people who know what they’re doing!


[1] MacLean et al (2011) Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness. J Psychopharmacol 25(11), p.1453-61.

[2] Carhart-Harris et al (2014) The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs. Front Hum Neurosci 3(8):20.

[3] Lyons & Carhart-Harris (2018) Increased nature relatedness and decreased authoritarian political views after psilocybin for treatment-resistant depression. J Psychopharmacol 32(7), p.811-819.

[4] French et al (2017) What is the evidence for the efficacy of self-help acceptance and commitment therapy? A systematic review and meta-analysis. Journal of Contextual Behavioral Science, 6, 360–374.

[5] Twohig & Levin (2017) Acceptance and commitment therapy as a treatment for anxiety and depression: A review. Psychiatric Clinics of North America, 40, 751–770.

[6] Kashdan & Rottenberg (2010) Psychological flexibility as a fundamental aspect of health. Clinical Psychology Review, 30, 865–878.

[7] Davis et al (2020) Psychological flexibility mediates the relations between acute psychedelic effects and subjective decreases in depression and anxiety. Journal of Contextual Behavioral Science 15, p.39-45.

[8] Watts & Luoma (2020) The use of the psychological flexibility model to support psychedelic assisted therapy. Journal of Contextual Behavioral Science 15, p.92-102.


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