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With great power comes great vulnerability: an ethical analysis of psychedelics’ therapeutic mechanisms proposed by the REBUS hypothesis
  1. Daniel Villiger1,
  2. Manuel Trachsel2
  1. 1 Department of Philosophy, University of Zurich, Zurich, Switzerland
  2. 2 Clinical Ethics Unit of University Hospital Basel and Psychiatric University Clinics, Basel, Switzerland
  1. Correspondence to Dr Daniel Villiger, Department of Philosophy, University of Zurich, Zollikerstrasse 117, 8008 Zürich, Switzerland; daniel.villiger{at}


Psychedelics are experiencing a renaissance in mental healthcare. In recent years, more and more early phase trials on psychedelic-assisted therapy have been conducted, with promising results overall. However, ethical analyses of this rediscovered form of treatment remain rare. The present paper contributes to the ethical inquiry of psychedelic-assisted therapy by analysing the ethical implications of its therapeutic mechanisms proposed by the relaxed beliefs under psychedelics (REBUS) hypothesis. In short, the REBUS hypothesis states that psychedelics make rigid beliefs revisable by increasing the influence of bottom-up input. Put differently, patients become highly suggestible and sensitive to context during a psychedelic session, amplifying therapeutic influence and effects. Due to that, patients are more vulnerable in psychedelic-assisted therapy than in other therapeutic interventions; they lose control during a psychedelic session and become dependent on the therapeutic setting (including the therapist). This enhanced vulnerability is ethically relevant and has been exploited by some therapists in the past. Therefore, patients in current research settings and starting mainstream medical settings need to be well informed about psychedelics’ mechanisms and their implications to give valid informed consent to treatment. Furthermore, other security measures are warranted to protect patients from the vulnerability coming with psychedelic-assisted therapy.

  • psychotherapy
  • psychopharmacology
  • informed consent
  • ethics
  • psychiatry

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  • Contributors DV drafted and revised the article and is responsible for the overall content as guarantor. MT commented on the article and made minor adjustments.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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