An international four‑round Delphi (89 experts from 17 countries) produced the ReSPCT guidelines: 30 consensus‑rated extra‑pharmacological variables, categorised into physical environment, dosing session procedure, therapeutic framework and subjective experiences. These guidelines provide a new standard to improve the design and reporting of set and setting in psychedelic clinical trials.
Psychedelic substances exhibit complex interactions with the ‘set and setting’ of use, that is, the mental state of the user and the environment in which a psychedelic experience takes place. Despite these contextual variables’ known importance, psychedelic research has lacked methodological rigor in reporting extra-pharmacological factors. This study aimed to generate consensus-based guidelines for reporting settings in psychedelic clinical research, according to an international group of psychedelic researchers, clinicians and past trial participants. We conducted a Delphi consensus study composed of four iterative rounds of quasi-anonymous online surveys. A total of 89 experts from 17 countries independently listed potentially important psychedelic setting variables. There were 770 responses, synthesized into 49 distinct items that were subsequently rated, debated and refined. The process yielded 30 extra-pharmacological variables reaching predefined consensus ratings:i.e., ‘important’ or ‘very important’ for ≥70% of experts. These items compose the Reporting of Setting in Psychedelic Clinical Trials (ReSPCT) guidelines, categorized into physical environment, dosing session procedure, therapeutic framework and protocol, and subjective experiences. Emergent findings reveal significant ambiguities in current conceptualizations of set and setting. The ReSPCT guidelines and accompanying explanatory document provide a new standard for the design and documentation of extra-pharmacological variables in psychedelic clinical research.
Psychedelic drugs are thought to interact strongly with contextual factors commonly referred to as 'set and setting'—the individual's mental state and the environmental, social and procedural context of use. The authors note that despite longstanding recognition of these influences, clinical research has lacked consistent, rigorous reporting of extra‑pharmacological variables, producing uncertainty about which non‑drug factors most affect outcomes and when they exert their effects. A recent systematic review cited by the authors found many trials failed to report even basic contextual features, limiting transparency and comparability across studies. This study set out to produce consensus‑based reporting guidance for extra‑pharmacological variables in psychedelic clinical trials. Using an international Delphi process, the investigators aimed both to generate a parsimonious, implementable checklist of setting variables warranting routine reporting and to probe how experts currently conceptualise the boundaries and temporality of 'set' and 'setting'. The resulting product is the Reporting of Setting in Psychedelic Clinical Trials (ReSPCT) guidelines, derived from input by clinicians, researchers and former trial participants across multiple countries and institutions.
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Schenberg, E. E. · Frontiers in Pharmacology (2018)
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Hartogsohn, I. · Drug Science Policy and Law (2017)
Vollenweider, F. X., Preller, K. H. · Nature Reviews Neuroscience (2020)
The study employed a four‑round Delphi consensus method, an iterative, quasi‑anonymous survey technique used to derive expert agreement on complex topics. Initial recruitment involved personalised email invitations to 149 experts plus 34 identified by snowballing; 89 experts consented and completed round 1. Panel composition aimed to include psychedelic clinicians, researchers and past clinical‑trial participants with relevant expertise in areas such as psychopharmacology, neuroimaging, psychedelic‑assisted therapy, trial design and harm reduction. Diversity was assessed using self‑reported sociodemographic and professional characteristics, and predefined subgroups were formed by gender, ethnicity, primary expertise, field and prior trial experience. Round 1 asked experts to list up to ten setting variables important to report; 770 free‑text responses were coded by the lead author and iteratively grouped by the lead authors into 49 distinct items. In round 2 (n = 73) experts rated each item for importance and for coherence (clarity of formulation), and provided optional feedback. Importance ratings were evaluated against predefined consensus thresholds (the study reports items reaching 'important' or 'very important' by ≥70% as consensus), while items with less than 90% coherence were revised. Subgroup analyses were used to detect minority consensus that might be missed by whole‑group voting, and items were assessed for uniqueness and implementability; overlapping items were combined, and items judged standard practice or problematic (for example privacy concerns) could be rejected. Round 3 (n = 68) presented modified items and proposed combinations for re‑rating; experts also voted on whether subjective items better reflecting 'set' should be retained, moved to an optional subsection, or excluded. Round 4 (n = 62) solicited feedback on the preliminary guidelines and on the study process, and included targeted questions about the separability, overlap and temporal boundaries of 'set' and 'setting'. Throughout, acceptance criteria included whole‑group importance ratings meeting thresholds, high coherence ratings (≥90% for coherence was used for modification decisions) and subgroup rescue of items where appropriate. Final guidelines were refined collaboratively with study leads and panel feedback and accompanied by an explanatory document and checklist.
The Delphi produced the 30‑item ReSPCT guidelines, organised into four sections: physical and sensory environment; dosing session procedure; therapeutic framework and protocol; and participant subjective experiences. Participation declined across rounds from 89 in round 1 to 62 in round 4 (a 30% attrition rate). Experts represented 17 countries and approximately 50 institutions, although the extracted text states that demographic and professional details are presented in a table not reproduced here. Round 1 generated 770 responses that were coded into 49 unique items; four items were mentioned by at least half the respondents: music and sound (n = 74), objects/decorations/artwork (n = 55), number of people present (n = 52), and access to nature (n = 46). In round 2, 33 of the 49 items (67%) met whole‑group consensus thresholds; one of these was removed because it duplicated standard clinical‑trial reporting. After quality checks for coherence, uniqueness and implementability, 17 items were accepted as written, 7 rejected and 27 were combined into 18. Subgroup analyses rescued several items that had not reached whole‑group consensus. Round 3 yielded further convergence: modified items met the 90% coherence threshold, proposed combinations exceeded 90% acceptance, and re‑ratings of previously subgroup‑consensus items added two items to whole‑group consensus. Experts voted to retain five items judged more subjective (pertaining to 'set') rather than exclude them; 46% supported keeping them as standard, 39% as an optional 'participant experience' subsection, and only 15% voted to exclude them. These steps produced a 30‑item preliminary guideline set. In round 4, at least 95% of respondents reported being satisfied or very satisfied with the preliminary guidelines and judged the process clear and successful. Regarding uptake, at least 74% said they would 'definitely' use the preliminary guidelines and 25% would 'consider' using them; only one expert (2%) said they would not. Responses about conceptualisation of set and setting were heterogeneous: 37% agreed or strongly agreed that set and setting can be studied separately, while 42% disagreed or strongly disagreed. Panel members estimated an average conceptual overlap of 49% between set and setting. On temporality, about 68% agreed that setting spans from recruitment to the end of follow‑up, 16% limited it to the treatment phase, and 10% to the dosing session. A notable item-level change was cultural competence and safety: it initially reached consensus only in some subgroups but, after debate, its whole‑group rating rose from 50% to 73%, securing its inclusion. The final ReSPCT package includes a downloadable checklist and explanatory document with item descriptions, reporting prompts and a literature summary.
Pronovo‑Morgan and colleagues present the ReSPCT guidelines as the first international consensus on which extra‑pharmacological variables should be routinely reported in psychedelic clinical trials. They argue the 30 items—covering environment, session procedures, therapeutic protocol and participant experience—are intended to improve transparency, reproducibility and comparability across studies, and to facilitate data aggregation and dismantling studies. The authors suggest the guidelines are applicable to multisite trials (with site‑specific details appended) and could support more pragmatic study designs that acknowledge and report contextual influences rather than attempting to mask them, a relevant point given the challenges of blinding in psychedelic research. The discussion highlights heterogeneity of expert views about what constitutes set versus setting, and the study team interprets this divergence as a likely contributor to inconsistent reporting practices. Rather than enforcing a strict dichotomy, the guidelines treat the 30 factors as interrelated. The authors note two items—cultural competence and cultural safety—were initially borderline but were included after panel debate emphasised concerns about power imbalances and lack of diversity. They also acknowledge limitations: the Delphi was survey‑based, which may have limited depth of dialogue; the panel was not fully representative of broader perspectives (most experts were relatively young, Western and 75–80% White); and the focus on clinical trials excluded nonclinical viewpoints. The authors emphasise that expert consensus does not equate to empirical truth and call for further empirical research to evaluate which contextual variables most strongly influence clinical outcomes. Finally, they present the ReSPCT materials (checklist and explanatory document) as resources to be used alongside trial reports to strengthen methodological rigour and to guide future research on drug‑context interactions.
In round 2 (n = 73), 33 of the 49 items (67%) from round 1 reached whole-group consensus thresholds. One of these, pertaining to aspects of the study protocol, was eliminated based on expert feedback that it is already subject to standard reporting practices in clinical trials, and 15 others were flagged for modification to address issues with coherence, uniqueness and/or implementability. At this stage, according to the study's original aims, items that were identified as being largely subjective-that is, pertaining more to set than to setting-were flagged for implementability issues. Of the 16 items not reaching whole-group consensus, 12 met the consensus threshold in one or more subgroups. Among them, one item was rejected for having a low coherence rating, and another was rejected because of potential privacy concerns for research study personnel. Two items were merged into items that had already reached whole-group consensus, and two other items were combined into a single item to address issues with overlap. The subgroup analyses thus yielded seven items to be debated in round 3. Overall, during round 2, 17 items were accepted as written, 7 items were rejected and 27 items were combined into 18 based on whole-and/ or subgroup feedback.
In round 3 (n = 68), all newly modified items met the 90% coherence threshold, and the proposed combinations of seven items into three new items surpassed 90% acceptance. Re-ratings of the seven debated items, which had previously reached only subgroup consensus (Supplementary Table), resulted in two items reaching whole-group consensus and thus being incorporated in the final guidelines (Table). Experts were also asked to vote regarding the potential inclusion of the five items collectively identified as referring more to set than to setting owing to their subjectivity. Despite the study's initial focus on setting variables, only 15% of experts voted to exclude these items from the guidelines. Rather, experts supported keeping these items as a standard component of the guidelines (46%) or as an optional subsection pertaining to 'participant experience' (39%). On the basis of these responses, these five items examining subjective experiences were included in the final section of the guidelines (Table). Overall, round 3 resulted in 13 additional items meeting criteria for acceptance. Added to the 17 accepted items from round 2, this produced the 30-item 'Preliminary guidelines for reporting setting in psychedelic clinical trials' (Supplementary Table) with an overview of each items' progression from round 1 to round 4 (Supplementary Table).
Results from the final round (n = 62) are presented in full in Supplementary Table. At least 95% of responding experts reported being satisfied or very satisfied with the preliminary guidelines, and either agreed or strongly agreed that they reflect what is important for reporting in psychedelic clinical trials. At least 74% of responding experts said they would 'definitely' use the preliminary guidelines, and 25% said they would 'consider it'; only 1 (2%) expert reported they would not. Feedback provided from the study experts expressing hesitation about using the preliminary guidelines (summarized in Supplementary Table) informed further improvements, which subsequently obtained approval from the study experts and culminated in the final guidelines presented below. Regarding the study methodology and process, at least 95% of experts rated the survey instructions as clear, the study structure as generally satisfactory, and both deadlines and time commitments as reasonable. Similarly, at least 95% evaluated the study as successful in identifying areas of agreement and disagreement, allowing opinions to be comfortably expressed, and ensuring that diverse voices had been adequately heard. Finally, 68% of experts reported that their aspects of their contexts, including study locations and physical environments. Such omissions limit the transparency and validity of psychedelic research; if psychedelic drug effects are indeed the product of drug-context interactions, methodologically rigorous research requires clear and reliable reporting of contextual variables. The primary aim of this study was to develop guidelines for reporting extra-pharmacological variables in psychedelic clinical trials, initially focused on settings, as has been done for other complex health interventions. We aimed to generate guidelines that were parsimonious, straightforward to implement and reflective of diverse perspectives. To achieve this objective, our study used the Delphi method, an evidence-based approach to deriving expert consensus on complex topics through iterative surveys. This method was selected for its capacity to integrate diverse forms of academic and experiential knowledge, to facilitate discourse across vast geographical regionsand to enable the productive exchange of knowledge across power differentials and hierarchies by preserving anonymity. To guide future research, the study also aimed to evaluate how set and setting are currently conceptualized in the field. In this study, 'experts' were defined as people 'having, involving, or displaying special skill or knowledge derived from training or lived experience'. Experts were recruited among psychedelic clinicians, psychedelic researchers and former psychedelic clinical trial participants with significant knowledge or experience in at least one of the following related areas: psychopharmacology, neuroimaging, psychedelic-assisted therapy, clinical trial design and/or harm reduction. Expert panel diversity was established based on self-reported sociodemographic characteristics and professional affiliations. This global Delphi study produced the Reporting of Setting in Psychedelic Clinical Trials (ReSPCT) guidelines, presented herein. Their 30 items represent the first international consensus regarding which specific non-pharmacological elements exert the most important influences on psychedelic drug effects, and thus warrant routine reporting in psychedelic clinical trials. These guidelines aim to significantly improve the quality of psychedelic research, much like other reporting guidelines have strengthened the evidence base of other clinical interventions.
Personalized email invitations to participate were initially sent to 149 experts, followed by an additional 34 experts identified by snowball recruitment. A total of 89 experts (48.6%) consented to participate, and all fully completed the first round. Thereafter, 73 experts completed round 2, 68 experts completed round 3 and 62 experts completed round 4, yielding a 30% attrition rate (Fig.).
The demographic and professional characteristics of the experts who completed the first and final rounds of this study are presented in Table, and affiliations are listed at the end of the article.
Round 1 (n = 89) prompted experts to list up to ten variables that they consider most important to report in psychedelic clinical trials and to provide an optional explanation for their choices. This yielded 770 free-text responses and rationales, which often related to trial participants' senses of safety and comfort under the influence of psychedelic drugs. These responses were then coded and grouped into a list of 49 unique items (Supplementary Table). Each item had been independently suggested by at least two experts, with four items mentioned by at least half of respondents: music and sound (n = 74); objects, decorations and artwork (n = 55); number of people present (n = 52); and access to nature (n = 46). conceptualization of setting had changed as a result of the study process, mostly in terms of the granularity, scope and depth with which they considered setting-related variables. The rates of reported changes in conceptualization did not differ between subgroups or geographical regions.
The final ReSPCT 2025 guidelines are presented in Table(fillable format in Supplement 1 in the Supplementary Information) and available on the ReSPCT website (). They were collaboratively refined from the preliminary guidelines by the study leads and experts. The guidelines are accompanied by a comprehensive explanatory document (Supplement 2 in the Supplementary Information), also produced collaboratively, which provides detailed descriptions of each item, suggested reporting prompts, supporting expert responses and a brief summary of the literature on the 30 ReSPCT items. The ReSPCT guidelines are composed of 30 items divided into 4 sections. The first section describes the physical and sensory environments to which participants are exposed during a dosing session, such as the study location, decorations and sensory reduction devices available to participants. The second section pertains to the dosing procedure, including the people present, music provided and interventions performed. The third section regards the trial's broader therapeutic framework and protocol, including preparatory and integration activities, and study personnel qualifications. The final section explores key aspects of participants' subjective experiences, including evaluations of therapeutic alliances, comfort, and both physical and psychological safety.
As detailed above, an emergent finding of the study's first three rounds was a lack of clarity and consensus regarding the conceptual boundaries between 'set' and 'setting'. Additional questions were thus posed to experts in round 4 to explore perspectives on this influential concept (Fig.). When asked to rate their agreement with the statement that set and setting can be studied separately, almost equal proportions agreed or strongly agreed (37%) and disagreed or strongly disagreed (42%). Experts were also asked to estimate the conceptual overlap between set and setting, from 0% to 100%. Responses again ranged widely, with nearly equal proportions of experts estimating conceptual overlap as 20-40%, 40-60% or 60-80%, yielding an average overlap rating of 49%. In addition, experts were asked to define the temporal boundaries of setting across the standard phases of psychedelic clinical trials. About 68% agreed that setting spans from the start of a clinical trial's recruitment to the end of its follow-up. Only 16% considered setting as limited to the trial's treatment phase-generally entailing preparation, dosing and integration subphases 1 -and 10% considered setting to be confined to the actual dosing session.
The ReSPCT guidelines The 30-item ReSPCT guidelines provide a new standard for the reporting of extra-pharmacological variables in psychedelic clinical trials, derived from an international Delphi consensus study of experts from 17 different countries and 50 different institutions. The contributing clinicians, researchers and past trial participants were selected to represent diverse forms of knowledge and perspectives, which were exchanged and debated throughout the iterative Delphi process. The final items span the physical environment of dosing sessions to important aspects of participants' experiences of psychedelic clinical trial settings. The guidelines, downloadable checklist (Supplement 1 in the Supplementary Information) and explanatory document (Supplement 2 in the Supplementary Information) can be found on the ReSPCT Guideline website (). The items of the ReSPCT guidelines are intended to be reported in the texts or supplements of future studies alongside a completed checklist (Supplement 1 in the Supplementary Information). In the case of multisite clinical trials, we recommend completing the whole guidelines based on the overarching study protocol and setting, and also specifying distinct features of each site by, for instance, including photographs of each treatment room. This practice aims to strengthen the design and documentation of clinical research on psychedelic drugs and thereby improve the transparency, reproducibility and validity of this rapidly evolving field. The adoption of these guidelines may also facilitate data comparison and aggregation across different groups and institutions, and inform future dismantling and therapeutic studies. Indeed, such issues recently prompted the US Food and Drug Administration to describe psychedelic therapies as a 'black box'and contributed to their recent rejection of 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy as a treatment for post-traumatic stress disorder. The ReSPCT guidelines were designed specifically for psychedelic clinical trials but may be adapted to other clinical and research contexts. For instance, they may be valuable in research involving other acutely psychoactive substances, given that potent drug-context interactions have been found with multiple non-psychedelic substances-including alcohol, antidepressants and opiates. In addition, the guidelines may facilitate more observational or pragmatic forms for psychedelic research. The challenges of blinding in psychedelic research may prove to be insurmountable; the ReSPCT guidelines could therefore support pragmatic study designs that prioritize the careful curation and systematic reporting of contextual variables over efforts to mask or minimize their influences.
The study revealed diverse initial views regarding the relative importance of various components of settings. Some of the final items, such as music and access to nature, were independently suggested by most experts in the first round and retained high agreement throughout the study. Others, such as narrative framings, and the positioning of people in treatment rooms, were mentioned by few but rapidly reached consensus thresholds thereafter. Two items that feature in the ReSPCT guidelines initially failed to reach whole-group consensus but were rescued by the debate process. For instance, in round 2, 'Cultural competence and safety' (item 25) reached consensus only in two subgroups. Cultural competence refers to a study team's ability to care for participants with diverse values, beliefs and behaviors, while cultural safety focuses on increasing health equity by encouraging healthcare professionals to examine power imbalances in patient-provider interactions. In round 3, multiple experts supported this item's importance, citing concerns regarding power imbalances and a lack of diversity in psychedelic clinical and research contexts. As a result, the item's whole-group rating increased from 50% to 73%, leading to its inclusion in the final guidelines. The study process also identified challenges associated with how set and setting is currently conceptualized. Despite the study's original focus on setting variables, early results and a subsequent vote led to the inclusion of five items that align more closely with the concept of (mind)set in the final guidelines' last section. In contrast to the consensus achieved regarding the relative importance of specific extra-pharmacological variables, expert views on the concept of set and setting itself remained highly heterogenous. For instance, in the final round, expert views were evenly divided regarding the perceived overlap and the separability of set and setting variables. The discrepant understandings of 'set and setting' among experts probably contributes to inconsistent reporting practices in psychedelic clinical trials. The ReSPCT guidelines aim to bypass this confusion with an explicit list of 30 key extra-pharmacological factors that are understood as interrelated, rather than as dichotomous. That is, a study's environment and therapeutic approach may interactively shape participant experiences, and those experiences may influence how extra-pharmacological factors are perceived or even adapted. The guidelines thus prioritize specificity over simplicity in the aim of improving psychedelic clinical research practices. Further study is needed to evaluate whether the utility of 'set and setting' outweighs its conceptual confusion in other contexts. Social determinants of health exert important influences on mental and physical well-being, and probably influence psychedelic clinical trial outcomes. However, social determinants are defined in diverse ways, and they may be challenging to accurately report owing to their breadth and complexity. a Cultural competence and cultural safety were originally two separate items that were merged as per expert feedback. BIPOC, Black, Indigenous, People of Color. Despite the study's strengths, several limitations must be acknowledged. First, the Delphi process was entirely survey based, which may have reduced the spontaneity and depth of dialog that can occur in face-to-face interactions. Second, the study's sample of experts did not represent the full diversity of perspectives on these drugs. For instance, the study's focus on clinical trials excluded broader, nonclinical perspectives on variables that shape psychedelic experiences. It also resulted in most experts being relatively young and originating from Western countries, where psychedelic clinical research is currently most highly concentrated. Relatedly, the study's definition of expertise reproduced known issues of the psychedelic field, namely, the current lack of racial diversity among psychedelic researchers and trial participants. This limitation was only partially overcome through the study's subgroup process, given that 75-80% of the sample was White. Finally, expertise does not necessarily equate to truth, and opinions of current psychedelic experts must be situated in the current historical moment and body of knowledge. Although this study intentionally enrolled experts with diverse views on psychedelic drugs, there was The ReSPCT guidelines serve as a reporting tool for settings in clinical trials with psychedelics. Each item should be reported in the main text or supplement of the resultant publication(s), the location of which should be indicated in the accompanying checklist (Supplement 1 in the Supplementary Information). The supporting explanatory document (Supplement 2 in the Supplementary Information) provides details and further guidance, including relevant research and suggested reporting prompts for each item. All documents can also be found on the ReSPCT website (). general agreement that psychedelic experiences and the contextual factors that shape them are clinically and scientifically important. The study did not include, for instance, experts who suggest that psychedelic drug experiences may be more akin to epiphenomena, which may have influenced the study's eventual findings. Further empirical research is needed to evaluate the actual importance of the variables that have been included in, or excluded from, the ReSPCT guidelines, and to discern those most relevant to clinical outcomes. The ReSPCT guidelines aim to advance the study of psychedelic drugs and therapies just as reporting guidelines have improved the transparency and interpretability of other complex clinical interventions. Its 30 items reflect a necessary, if preliminary, expert consensus regarding the most important contextual factors to report in studies of psychedelic drugs. The accompanying explanatory document serves to facilitate reporting and guide future research by synthesizing the current literature regarding contextual influences on psychedelic drug effects. The most up-to-date version of the ReSPCT guidelines and associated documents can be found at. Routine utilization of these guidelines could significantly improve the rigor of psychedelic research, mitigate the ambiguities of current understandings of set and setting, advance our understanding of drug-context interactions, and potentially facilitate the future clinical implementation of these promising therapies in safe, transparent and effective ways.
Any methods, additional references, Nature Portfolio reporting summaries, source data, extended data, supplementary information, acknowledgements, peer review information; details of author contributions and competing interests; and statements of data and code availability are available at.
The first survey underwent pilot acceptability and fidelity testing with six independent experts, including the two cofounders of PsyPAN. In round 1, all experts were asked to list up to ten setting variables they deemed most important for reporting in psychedelic clinical trials, with the option to provide their rationale for each. The lead author (C.P.-M.) first coded all free-text responses in a nonhierarchical manner. Subsequently, the three lead authors collaboratively grouped these codes into broader themes and iteratively refined them to improve clarity and reduce redundancy. This process yielded a preliminary list of distinct items, organized into preliminary sections, with item descriptions summarizing the details and rationales provided by experts.
In round 2, experts were provided with the list of items and descriptions generated in round 1. For each item, experts were asked to rate the importance of its inclusion in the reporting guidelines and its coherence, that is, the clarity of its formulation and description, and to optionally provide additional feedback. Importance ratings were analyzed according to the consensus threshold, both for the entire group and within predefined subgroups of experts according to gender, ethnicity, primary type of expertise, field of expertise and previous clinical trial experience (Supplementary Table). Subgroup analyses are not universal in Delphi studies, but were conducted to identify minority opinions that may otherwise have been overlooked. Items that reached consensus in the entire group or in any subgroup then underwent quality analyses based on coherence, uniqueness and implementability. Coherence was based on experts responding 'yes', 'no' or 'unsure' to the prompt 'I think this item is coherent/logical'. Uniqueness and implementability were established based on solicited free-text feedback. Items with less than 90% coherence ratings were modified according to expert feedback; items lacking uniqueness were combined with other overlapping items; items identified as having potential implementability issues were flagged for reconsideration.
In round 3, experts were asked to reevaluate the items that had reached consensus but had issues with coherence, uniqueness and/or implementability. For items modified to address coherence issues, experts re-rated the modified item's importance and coherence. For items combined to reduce excessive overlap, experts indicated whether they agreed or disagreed with the proposed combinations. For items with identified implementability issues, experts voted whether to keep them in the core guidelines, move them to a separate optional subsection or remove them altogether. Experts were also asked to debate items that reached consensus in at least one subgroup but not across the full sample. They were presented with each debated item's importance scores for the entire group and for the subgroup(s) in which the item reached consensus, alongside representative quotes spanning the divergent opinions. They then re-rated the debated item's importance based on this additional information. Lastly, experts were presented with a table of items that did not reach consensus in any subgroup and invited to voice any final opposition to their rejection from the guidelines.
In round 4, experts were asked to provide feedback on the preliminary reporting guidelines developed over the previous three rounds and to rate the perceived quality of the study process. In addition, based on emergent findings of the previous rounds, experts were asked to rate the conceptual overlap, separability and temporal boundaries of set and setting, and to report whether their understanding of this concept Ruffell is the cofounder of Onaya Science, a not-for-profit research organization, and the CEO of Onaya, an organization that delivers psychedelic mentorship training courses. He is also the chief medical officer of MINDS, a not-for-profit research organization. K.T. works with Lykos as a therapist and educator. The other authors declare no competing interests.
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