From Relaxed Beliefs Under Psychedelics (REBUS) to Revised Beliefs After Psychedelics (REBAS): Preliminary Development of the RElaxed Beliefs Questionnaire (REB-Q)
Richard J. Zeifman, Meg J. Spriggs, Hannes Kettner, Taylor Lyons, Fernando E. Rosas, Pedro A. M. Mediano, David Erritzøe, Robin Carhart-Harris
July 7, 2022 preprint DOI: 10.31234/osf.io/w8j6t (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Within-subjects experimental study |
|---|---|
| Sample size | 11 |
| Population | Healthy individuals |
| Intervention | Psilocybin |
| Dose | 1 mg and 25 mg |
| Duration | 4-week interval between dosing sessions; follow-up at 4 weeks after each session |
| Topics | Psilocybin |
| Keywords | Confidence interval Clinical psychology Hypnosis |
| Citations | 13 |
| Key findings | A high dose of psilocybin reduced confidence in negative self-beliefs, and this reduction was associated with greater brain entropy and improved well-being four weeks later. |
Abstract
Background: The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs, and offers a unified account of the acute and therapeutic action of psychedelics. Although REBUS has received some neuroscientific support, little research has examined its psychological validity. We conducted a preliminary examination of two psychological assumptions of REBUS: (a) psychedelics foster acute relaxation and post-acute revision of confidence in mental-health-relevant beliefs; (b) this relaxation and revision facilitates positive therapeutic outcomes and is associated with the entropy of EEG signals (an index of neurophysiological mechanisms relevant to REBUS).
Method: Healthy individuals (N=11) were administered 1 mg and 25 mg psilocybin 4-weeks apart. Confidence ratings for personally held negative and positive beliefs were obtained before, during, and 4-weeks after dosing sessions. Acute entropy and self-reported subjective experiences were measured, as was well-being (before and 4-weeks after dosing sessions).
Results: Confidence in negative self-beliefs decreased following 25 mg psilocybin and not following 1 mg psilocybin. Entropy and subjective effects under 25 mg psilocybin correlated with decreases in negative self-belief confidence (acute and 4-weeks after dosing). Particularly strong evidence was seen for a relationship between decreases in negative self-belief confidence and increases in well-being at 4-weeks.
Conclusions: We report the first empirical evidence that the relaxation and revision of negative self-belief confidence mediates positive psychological outcomes; a psychological assumption of REBUS. Replication within larger and clinical samples remains necessary. We also introduce a new measure, the Relaxed BEliefs Questionnaire (REB-Q), for examining the robustness of these preliminary findings and the utility of the REBUS model.