Riccardo Miceli McMillan

Current evidence suggests that the efficacy of psychedelic therapy depends, in part, on the character of psychedelic experiences themselves. One pronounced aspect of psychedelic experiences is alterations to the experience of time, including reports of timelessness or transcending time. However, how we should interpret such reports remains unclear, and this lack of clarity has philosophical and clinical implications. For instance, “true” timelessness may be considered antithetical to having any experience at all, and descriptions of experiences involving “timelessness” are known to be diverse and of varying clinical significance. In this article, we utilize a phenomenological approach to the study of temporality to highlight ambiguities in current constructs used to assess psychedelic experiences. In doing so, we advance some preliminary phenomenological accounts of psychedelic therapy’s mechanisms of action, such as psychedelic temporality acting as a kind of counterpoint for depressive temporality. We conclude by outlining how a dedicated phenomenological research program can provide a nuanced map of psychedelic temporality, guiding future research in a manner that addresses both philosophical and clinical ambiguities.

Psychedelic-assisted therapy (PAT) is an emerging intervention in psychiatry, for which there is preliminary evidence for effectiveness in eating disorders (EDs). The subjective psychedelic experience is considered an important driver of positive outcomes following PAT; however, conventional study design approaches often overlook many of the nuances inherent to the experience. Consequently, considerable information is lost between the first-person account and its scientific interpretation and documentation. Phenomenology—a philosophical and empirical approach to studying lived experience—offers tools to assess and understand the experiential mechanisms of PAT. This commentary advances the case for a phenomenological approach to PAT research in EDs, focusing on key domains of experience that underlie both ED psychopathology and psychedelic experiences, including embodiment, intersubjectivity, affectivity, temporality, spatiality and selfhood. We define and outline these phenomenological domains of EDs and psychedelic experiences and critically examine current measurement approaches. Following, we provide specific research recommendations, including phenomenologically grounded qualitative research and microphenomenology (i.e., the assessment of short-lived, pre-conscious experiences), to more fully capture psychedelic experiences and determine their significance for ED outcomes. The application of phenomenology to the PAT study design may contribute to a better understanding of how individuals experience PAT and generate testable hypotheses to advance psychedelic interventions.

Psychedelic-Assisted Psychotherapy is being investigated as a treatment for a range of psychiatric illnesses. Current research suggests that the kinds of subjective experiences induced by psychedelic compounds play key roles in producing therapeutic outcomes. To date, most knowledge of therapeutic psychedelic experiences are derived from psychometric assessments with scales such as the Mystical Experience Questionnaire. While these approaches are insightful, more nuanced and detailed descriptions of psychedelic-induced changes to subjective experience are required. Drawing on recent advancements in qualitative methods arising from the interdisciplinary field of phenomenological psychopathology, we propose a systematic and comprehensive investigation into how Psychedelic-Assisted Psychotherapy alters subjective experience. This research program aims to characterise the nature of therapeutic psychedelic experiences by drawing on concepts from philosophical phenomenology. Such characterisations should, moreover, contribute to our understanding of the mechanisms of psychedelic therapy, the role of integration therapy, and related philosophical debates.

The recent renaissance in research on psychedelic-assisted psychotherapy is showing great promise for the treatment of many psychiatric conditions. Interestingly, therapeutic outcomes for patients undergoing these treatments are predicted by the occurrence of a mystical experience—an experience characterised in part by a sense of profound meaning. This has led to hypotheses that psychedelic-assisted psychotherapy is therapeutic because it enhances perception of meaning, and consequently leads to a meaning response (a therapeutic mechanism that has been well described in the philosophical literature on the placebo effect). The putative mechanism of action of psychedelics as meaning enhancers raises normative ethical questions as to whether it can be justified to pharmacologically increase the perception of meaning in order to heal patients. Using the perspectives of hedonistic moral theories, this paper argues that if psychedelics operate as meaning enhancers, psychedelic-assisted psychotherapy can be ethically justified. An anti-hedonistic objection is presented by applying Robert Nozick’s Experience Machine thought experiment to the case of psychedelic-assisted psychotherapy. However, it is argued that this objection falls short for two reasons. First, even if pleasure and pain are not the only consequences which have moral value they are not morally irrelevant, therefore, therapeutic meaning enhancement can still be justified in cases of extreme suffering. Second, it is possible that psychedelic states of consciousness do not represent a false reality, hence their therapeutic meaning enhancement is not problematic according to Nozick’s standards.

Psychedelic-assisted Psychotherapy combines the use of psychedelic compounds, such as psilocybin, with psychotherapy. PAP has shown some promise as a novel treatment for Major Depressive Disorder, and empirical research suggests that its efficacy turns on the altered states induced by psychedelic compounds. In this paper we draw on the literature of phenomenology to explain the therapeutic potential of psychedelic experiences. Svenaeus characterises mental illness as a form of suffering that entails three distinct but related experiences of alienation or “unhomelike being-in-the-world”: illness suffering, which relates to embodiment; existential suffering, which relates to self-narratives, and political suffering, which relates to social relationships. Ratcliffe further characterises the experience of MDD in phenomenological terms as a loss of pre-intentional possibility that manifests as excessive noematic feeling in the experience of embodiment, restrictive narratives in the construction of self, and disconnectedness in experience of the social world. We contend that PAP ameliorates the suffering associated with MDD by inducing and consolidating a state of broadened pre-intentional possibility—one that entails sudden, profound and enduring changes in embodiment, self-narratives, and social experience. We argue further that this phenomenological account is consistent with a bio-psycho-social model of mental health and illness, and we frame it as an argument supporting the plausibility of recent claims about treatment success. This helps to justify ongoing future empirical research in this setting.