For decades, practitioners and researchers have spoken of set and setting as the twin pillars of a psychedelic experience — yet until recently, no one had rigorously measured either. The idea that preparation matters was widely held, rarely questioned, and almost never formally tested. That changed in 2024, when a team at University College London published the first psychometrically validated scale for measuring psychedelic preparedness. What they found is worth examining carefully — not because it confirms what we already believed, but because it tells us something more precise, and more useful, than intuition alone.

What Do We Mean by “Readiness”?

In everyday conversation, being ready for a psychedelic experience might mean feeling calm, or having done some reading, or simply being willing to proceed. The scientific literature proposes something more structured. Carhart-Harris and colleagues (2018) drew attention to the concept of context — encompassing both the internal state of the person and the external conditions of the experience — as a core determinant of outcomes. They noted that 5-HT2A receptor agonism, the primary pharmacological mechanism of classic psychedelics, renders these compounds uniquely sensitive to context in ways that most other psychoactive substances are not. Set and setting, in other words, are not incidental features of the experience. They are pharmacologically relevant.

Building on this foundation, McAlpine, Blackburne and Kamboj (2024) defined psychedelic preparedness as the psychological, physical, and social state of being ready for both the content and the consequences of a psychedelic experience — before it occurs. Using a novel iterative methodology combining Delphi expert rounds with lived-experience focus groups (the “DelFo” method), they developed and validated the 20-item Psychedelic Preparedness Scale (PPS), which identifies four distinct domains:

• Knowledge-Expectations: Understanding what effects the substance may produce, including the possibility of intense emotions or altered perceptions
• Intention-Preparation: Having a clear reason for the experience and having engaged in deliberate preparatory practices such as meditation, journalling, or psychoeducation
• Psychophysical-Readiness: Feeling psychologically and physically prepared to meet whatever arises, including a willingness to surrender to the process
• Support-Planning: Having trusted people around the experience, knowing what to do if things become difficult, and having a plan for the hours and days after

This four-factor model demonstrated excellent overall reliability (McDonald’s omega ω = 0.945) and good test-retest reliability across its subscales. Critically, items were not generated by researchers alone but were co-produced with individuals who had lived experience of psychedelic-assisted psychotherapy — a methodological choice that shaped both the content and the language of the scale (McAlpine et al., 2024).

What the Research Has Found

The PPS was administered retrospectively to two large online samples of psychedelic users (Study 2 combined N = 1,236) and prospectively to participants in a 5–7-day psilocybin retreat (Study 3, N = 46). Across both designs, higher preparedness scores were consistently associated with better outcomes.

In the pooled retrospective sample, participants who scored above the median on the PPS (the “High Preparation” group) showed significantly better outcomes on all six criterion measures compared to those below the median (McAlpine et al., 2024): greater mystical experience, greater emotional breakthrough, more post-psychedelic growth, higher centrality of the event in personal narrative, greater perceived wellbeing, and fewer challenging experiences — the only outcome where low preparation scored higher.

In the prospective retreat study, pre-experience PPS scores significantly predicted the quality of the experience itself — indexed by global altered states of consciousness (r = 0.56, p < 0.001) — as well as reductions in depression (r = −0.45, p = 0.002), anxiety (r = −0.53, p < 0.001), and stress (r = −0.56, p < 0.001) assessed two weeks after the retreat (McAlpine et al., 2024).

“The results of this study provide preliminary evidence that positive preparatory context is associated with greater therapeutic change.”
— McAlpine, Blackburne & Kamboj (2024, p. 11), Scientific Reports

These findings do not stand alone. An earlier prospective naturalistic study by Haijen, Kaelen, Roseman and colleagues (2018) collected data from individuals before they took a psychedelic of their own initiative and found that a positive pre-experience “set” — encompassing openness, surrender, and clear intentions — significantly reduced the likelihood of a challenging experience. The temporal design of this study (data collected before the experience) is important: it strengthens the case for a preparedness-to-outcome pathway rather than retrospective attribution.

A systematic review by Aday, Davis, Mitzkovitz and colleagues (2021) synthesised 14 studies on baseline predictors of acute psychedelic reactions. The review found consistent evidence that individuals high in absorption, openness, and the dispositional capacity for psychological surrender were more likely to report positive and mystical-type experiences, while those in apprehensive, confused, or preoccupied pre-experience states were more likely to experience acute adverse reactions. These findings converge with the Psychophysical-Readiness and Knowledge-Expectations domains of the PPS without being derived from it.

What This Research Does Not Show: Three Misconceptions Worth Naming

The evidence described above is meaningful. It is also limited in ways the researchers themselves are explicit about, and it is worth naming those limits directly rather than passing over them.

1. Correlation is not causation

The association between PPS scores and outcomes in Study 2 is correlational. People who score high on preparedness may differ from low-scorers in ways not fully captured by the scale — in trait openness, prior experience, socioeconomic access to quality preparation resources, or other variables. The prospective retreat data (Study 3) provides stronger temporal evidence, but the sample size (N = 46) is too small to support broad causal conclusions. Describing preparation as a determinant of outcomes is an overclaim the paper itself does not make.

2. Preparation does not guarantee a positive experience

High PPS scores predict better outcomes on average, across groups. They do not guarantee any individual’s experience. Psychedelic experiences remain inherently variable, and challenging moments can arise even for those who are thoroughly prepared. The evidence suggests preparation reduces the likelihood and severity of difficulty; it does not eliminate it. This distinction matters, particularly for people who may hold unrealistic expectations about what preparation can deliver.

3. The PPS is not a clinical screening or diagnostic tool

McAlpine et al. state explicitly: “the PPS should not be utilised as a standalone diagnostic tool for making clinical decisions, but rather integrated with other comprehensive clinical assessments as part of a comprehensive treatment plan.” The scale also draws primarily from WEIRD (White, Educated, Industrialised, Rich, Democratic) samples — a limitation the authors acknowledge and which limits the generalisability of current findings to broader and more diverse populations.

Preparation Is Not a Checklist

A systematised review of the preparation literature in substance-assisted psychotherapy by Thal, Wieberneit, Sharbanee and colleagues (2022) synthesised 83 sources and found broad consensus that structured preparation is considered essential before the administration of psychoactive substances in clinical contexts. The review identified a range of preparatory practices — psychoeducation, intention-setting, breathwork, therapeutic relationship building, safety planning — that appear across multiple treatment protocols, even where those protocols differ considerably in other respects.

What this review and the PPS together suggest is that readiness is not a single thing one either has or does not have. It is a multi-dimensional state built across the four domains identified by McAlpine et al.: what you understand about what may happen; what you intend from the experience; how prepared your body and mind are to meet whatever arises; and who stands beside you. Each of these is a domain of active work, not passive accumulation.

Modlin, Miller and Rucker (2023), writing from a clinical perspective at King’s College London, propose that readiness assessment in psilocybin therapy should give equal weight to intrapersonal factors — including a patient’s motivations, their capacity for affective tolerance, and their current psychological stability — and interpersonal factors, including the quality of the therapeutic relationship. Preparedness, in this framing, is not a pre-existing trait to be discovered but a dynamic state to be cultivated, collaboratively, in the time before an experience begins.

How Full Circle Journeys Approaches Preparation

At Full Circle Journeys, we do not treat preparation as a series of boxes to tick before the date arrives. The evidence — and our experience — suggests it is where much of the meaningful work begins. Our approach to preparation is grounded in science and tradition, drawing on the four domains of readiness identified in the current research: building honest knowledge of what the experience may involve; working with intention, not assumption; attending carefully to physical and psychological readiness; and ensuring that each person has a genuine support structure in place — before, during, and after.

We walk beside you — not ahead of you. Preparation at Full Circle is not prescriptive. It is relational and responsive, shaped by who you are and what you are bringing to the experience. Whatever arises, belongs — and part of our work together is building the foundation from which you can meet it.