Therapy Undefined: What Psychedelic Studies Don’t Tell Us

As alluded to in the prior piece, and earlier reporting by Psychedelic Alpha, terms like ‘psychedelic therapy’, ‘psychedelic-assisted therapy’, and even ‘therapy’ itself often flatten what is in reality a broad and sometimes messy provision.

In an attempt to clarify which specific types of therapy or support are most commonly used across the psychedelic landscape, both in general and in relation to specific clinical indications, we conducted a brief, non-exhaustive survey of published trials and review data. We found that many trials failed to characterise the therapy intervention at all, while others offered only vague descriptions.

Indeed, a 2022 systematic review found that most psychedelic trial reports fall short here. Of 15,470 unique articles initially screened, only 391 proceeded to full-text review. Ultimately, just 55 studies (including 10 identified elsewhere) met the inclusion criteria of employing a clearly defined, structured psychological intervention. References to “psychological support” or “psychotherapy sessions” were common, but were rarely accompanied by specifics, and while some studies mention “preparation” and “integration” phases, the majority omit whether a therapy manual was used or if sessions followed any structured format. Among those that did provide more detail, Cognitive Behavioural Therapy (CBT) cropped up frequently, as did compound-specific approaches such as MDMA-Assisted Psychotherapy and Ketamine Enhanced Therapy.

Other surveys have revealed similar gaps. A 2025 review by European Medicines Agency authors reported that, of eight completed psychedelic trials for depression, only two mentioned ‘psychotherapy’, and the term notably lacked a standardised definition. 

Our own search echoed this lack of clarity. The specifics often came down to therapists’ discretion, with some published studies and protocols listing eclectic blends of modalities, including psychodynamic, mindfulness-based, ACT, parts work, and so on. Similar ambiguity surrounds practitioner titles, including therapist, guide, mentor, or monitor, and the inconsistent labelling of post-session support, variously called “integration”,“debriefing,” or “follow-up.”

Those of you working as research-oriented practitioners will know that therapeutic support in psychedelic trials often does necessitate some form of structure (at least in terms of content that must be covered during preparation and integration sessions). Many use comprehensive therapy manuals and often require extensive training for therapists.

So why don’t these details make it into the published literature? And why does this matter?

The lack of reporting may stem from several factors. When publications omit or limit therapy details, it creates space for sponsors, or other stakeholders, to claim minimal, or zero, (psycho)therapeutic provision. Since the FDA doesn’t regulate psychotherapy, omitting it from protocols simplifies the story and, as we alluded to earlier, could lend itself to scalability.

But a lack of transparency or detail in publications has raised concerns. Replicability is a core tenet of scientific inquiry, yet without clear documentation of methodology, it becomes near impossible to achieve. As Max Wolff and colleagues have noted, in the absence of robust experimental data and consistent reporting on contextual factors, research-oriented practitioners will need to rely on complementary sources to guide their practice. Those include observational studies, surveys of naturalistic use, and controlled lab studies with healthy volunteers.

Further still, some claim that, regardless of a sponsor’s claims, some form of therapy or its elements is almost always present, especially in current trials where FDA’s draft guidance suggests that the lead study monitor be a healthcare provider with professional training and clinical experience in psychotherapy, among other things.

Efforts to build consensus in reporting are underway. An international team of experts has developed the ReSPCT guidelines: a 30-item checklist designed for use by clinical trialists to ensure the useful documentation of key contextual factors (e.g., the physical environment, support person credentials, prep and integration activities). In late September, David Nutt and colleagues also proposed a lexicon to describe various factors of psychedelic protocols. By providing a standardised framework, the guidelines aim to establish a shared reference point across the field, mitigating definitional inconsistencies, enhancing replication, and enabling our discernment of the true potential of psychedelics.

Bottom Line: We might expect industry-sponsored trials to continue to be thin on their reporting of non-drug factors, or the ‘setting’, in their published studies, given their focus on simplifying the story for regulators and delivering a minimal model of support. But we should hope that academic researchers embrace the key messages of the ReSPCT guidelines, for example, to increase the interpretability of the growing psychedelic clinical dataset to allow practitioners to draw inferences about best practices. Funders, too, might consider adherence to such guidelines when deciding which projects to support.