New research reveals how psilocybin weakens negative self-beliefs and enhances mental well-being by increasing neural entropy, unlocking new possibilities for psychedelic therapy.
Study: From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS). Image Credit: Daniel Patrick Martin / Shutterstock
In a recent study published in the journal Scientific Reports, a group of researchers investigated whether psilocybin acutely and in the long term reduces confidence in negative self-beliefs and how these changes correlate with neural entropy, unitive experiences, and well-being.
Background
Every year, millions struggle with mental health conditions resistant to conventional treatments. Depression, anxiety, and rigid negative self-perceptions persist despite pharmacological and psychotherapeutic interventions. Recent studies suggest psychedelics like psilocybin offer transformative experiences by altering entrenched cognitive patterns.
The Relaxed Beliefs Under Psychedelics (REBUS) model proposes that psychedelics temporarily reduce the brain’s hierarchical organization, enabling flexible thinking. However, the long-term psychological mechanisms remain unclear. This study introduces an extension of the REBUS model, called REvised Beliefs After Psychedelics (REBAS), which suggests that psilocybin not only relaxes cognitive rigidity in the short term but also facilitates sustained revision of maladaptive beliefs. This post-acute restructuring may be crucial for long-term therapeutic effects, particularly in clinical applications.
Do psychedelics merely relax cognitive rigidity during the acute phase, or do they facilitate lasting revision of maladaptive beliefs? Understanding this process could redefine mental health treatment. However, further research is needed to confirm these effects, particularly in larger and more diverse populations, including clinical samples.
About the Study
The present study examined psilocybin’s effects on belief confidence, neural entropy, and well-being in 11 healthy, psychedelic-naïve individuals (4 females, mean age = 42 years). The small sample size limits the generalizability of findings, particularly to clinical populations. Participants underwent two sessions, receiving 1 mg of psilocybin in the first and 25 mg four weeks later in a fixed-order, single-blind design.
Belief confidence was measured before, during, and four weeks after each session using the Relaxed Beliefs Questionnaire (REB-Q). Subjective unitive experiences were assessed with the Altered States of Consciousness (ASC) questionnaire, and well-being was evaluated using the Warwick-Edinburgh Mental Well-being Scale (WEMWBS).
Resting-state electroencephalogram (EEG) recordings were taken at baseline, 1 hour, 2 hours, and 4.5 hours post-administration to measure neural entropy, a marker of cognitive flexibility. Statistical analyses included repeated-measures Analysis of Variance (ANOVA) and Bayesian hypothesis testing, which provided stronger evidence than traditional statistical methods given the small sample size.
Psilocybin administration occurred in a controlled environment with therapeutic support. The study followed ethical guidelines and received all necessary approvals. The analysis focused on whether psilocybin acutely reduced belief confidence and whether these effects persisted after four weeks, and how these changes related to neural entropy and unitive experiences.
Study Results
Following 25 mg of psilocybin, negative self-belief confidence showed a moderate and significant decrease four weeks after administration, supported by substantial Bayesian evidence (BF > 3), while no such effect occurred with 1 mg. Acutely, moderate but non-significant reductions in negative self-belief confidence were observed. Interestingly, positive self-belief confidence significantly increased four weeks after the higher dose, suggesting psilocybin weakens maladaptive beliefs while strengthening adaptive ones. Negative beliefs about others showed minor acute reductions but did not persist.
A strong correlation emerged between acute unitive experiences and reductions in negative self-belief confidence, both acutely and four weeks later. This relationship was only observed after the 25 mg dose, not the 1 mg dose, highlighting the dose-dependent nature of the effects. The intensity of the unitive experience reliably predicted sustained belief change, reinforcing the role of subjective psychedelic effects in cognitive restructuring.
Additionally, acute reductions in negative self-belief confidence strongly correlated with increases in well-being four weeks after 25 mg psilocybin. These findings align with research linking decreased pessimism to improved mental health outcomes.
Neural entropy was significantly associated with reductions in negative self-belief confidence. Specifically, entropy measured at 1 hour and 2 hours post-25 mg administration correlated with both acute and long-term belief changes, but no significant associations were observed at 4.5 hours. The lack of an effect at 4.5 hours suggests that early post-administration changes in neural entropy may be critical for predicting lasting belief change. No such associations were observed for 1 mg psilocybin, supporting the hypothesis that high-dose psilocybin induces a neural state conducive to cognitive restructuring. Increased entropy likely represents a biological marker of flexible cognition, allowing entrenched beliefs to weaken and positive beliefs to form.
These findings provide preliminary support for both the REBUS and REBAS models by demonstrating that psilocybin induces both acute relaxation and long-term revision of negative self-beliefs. REBAS suggests that lasting therapeutic benefits depend on post-acute integration processes, reinforcing the importance of guided therapy and reflective practices following psilocybin use. The connection between unitive experiences, neural entropy, and belief changes suggests that psychedelic therapy operates through both subjective and neurobiological mechanisms.
However, the study’s small sample size and the use of healthy participants limit the generalizability of these findings. Further research is needed to confirm these effects in clinical populations, particularly individuals with depression, anxiety, or other mental health conditions characterized by rigid negative self-beliefs.
Conclusions
To summarize, mental health disorders often persist due to rigid negative self-beliefs, limiting treatment success. This study demonstrates that psilocybin not only relaxes these beliefs acutely but also promotes lasting cognitive revision, supporting both the REBUS and REBAS models. Increased neural entropy appears to enhance cognitive flexibility, enabling long-term belief changes.
A key finding is that unitive experiences strongly predict sustained improvements, highlighting the role of both psychological and neurobiological mechanisms in psilocybin therapy. Notably, reductions in negative self-belief confidence correlated with enhanced well-being, suggesting a direct link between cognitive restructuring and mental health benefits.
However, the study’s preliminary nature and small sample size underscore the need for replication in larger and more diverse populations, including individuals with clinical diagnoses. By disrupting entrenched cognitive patterns, psilocybin may offer a breakthrough treatment for depression and anxiety, but further research is needed to confirm these effects and optimize therapeutic protocols.