From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS)
The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs. We conducted a preliminary examination of two psychological assumptions of REBUS: (a) psychedelics foster acute relaxation and post-acut...
| Main Authors: | , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Nature Research
2025
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| _version_ | 1824459169795670016 |
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| author | Zeifman, RJ Spriggs, MJ Kettner, H Lyons, T Rosas, FE Mediano, PAM Erritzoe, D Carhart-Harris, RL |
| author_facet | Zeifman, RJ Spriggs, MJ Kettner, H Lyons, T Rosas, FE Mediano, PAM Erritzoe, D Carhart-Harris, RL |
| author_sort | Zeifman, RJ |
| collection | OXFORD |
| description | The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs. 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; which (b) facilitate positive therapeutic outcomes and are associated with the entropy of EEG signals. Healthy individuals (N = 11) were administered 1 mg and 25 mg psilocybin 4-weeks apart. Confidence ratings for personally held beliefs were obtained before, during, and 4-weeks post-psilocybin. Acute entropy and subjective experiences were measured, as was well-being (before and 4-weeks post-psilocybin). Confidence in negative self-beliefs decreased following 25 mg psilocybin. Entropy and subjective effects under 25 mg psilocybin correlated with decreases in negative self-belief confidence (acutely and at 4-weeks). Particularly strong evidence was seen for a relationship between decreases in negative self-belief confidence and increases in well-being. We report the first empirical evidence that the relaxation and revision of negative self-belief confidence mediates psilocybin's positive psychological outcomes, and provide tentative evidence for a neuronal mechanism, namely, increased neuronal entropy. Replication within larger and clinical samples is necessary. We also introduce a new measure for examining the robustness of these preliminary findings and the utility of the REBUS model. |
| first_indexed | 2025-02-19T04:37:31Z |
| format | Journal article |
| id | oxford-uuid:324b4dc8-74ee-4d4e-9407-fc87a0d9ecfb |
| institution | University of Oxford |
| language | English |
| last_indexed | 2025-02-19T04:37:31Z |
| publishDate | 2025 |
| publisher | Nature Research |
| record_format | dspace |
| spelling | oxford-uuid:324b4dc8-74ee-4d4e-9407-fc87a0d9ecfb2025-02-07T20:03:37ZFrom relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS)Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:324b4dc8-74ee-4d4e-9407-fc87a0d9ecfbEnglishJisc Publications RouterNature Research2025Zeifman, RJSpriggs, MJKettner, HLyons, TRosas, FEMediano, PAMErritzoe, DCarhart-Harris, RLThe Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs. 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; which (b) facilitate positive therapeutic outcomes and are associated with the entropy of EEG signals. Healthy individuals (N = 11) were administered 1 mg and 25 mg psilocybin 4-weeks apart. Confidence ratings for personally held beliefs were obtained before, during, and 4-weeks post-psilocybin. Acute entropy and subjective experiences were measured, as was well-being (before and 4-weeks post-psilocybin). Confidence in negative self-beliefs decreased following 25 mg psilocybin. Entropy and subjective effects under 25 mg psilocybin correlated with decreases in negative self-belief confidence (acutely and at 4-weeks). Particularly strong evidence was seen for a relationship between decreases in negative self-belief confidence and increases in well-being. We report the first empirical evidence that the relaxation and revision of negative self-belief confidence mediates psilocybin's positive psychological outcomes, and provide tentative evidence for a neuronal mechanism, namely, increased neuronal entropy. Replication within larger and clinical samples is necessary. We also introduce a new measure for examining the robustness of these preliminary findings and the utility of the REBUS model. |
| spellingShingle | Zeifman, RJ Spriggs, MJ Kettner, H Lyons, T Rosas, FE Mediano, PAM Erritzoe, D Carhart-Harris, RL From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) |
| title | From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) |
| title_full | From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) |
| title_fullStr | From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) |
| title_full_unstemmed | From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) |
| title_short | From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS) |
| title_sort | from relaxed beliefs under psychedelics rebus to revised beliefs after psychedelics rebas |
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