Psilocybin therapy improves self-beliefs, increases neural entropy

Key takeaways:

• Eleven healthy volunteers received low and high doses of psilocybin 4 weeks apart.
• High dose was associated with decreased negative self-belief and an increase in well-being.

MIAMI BEACH, Fla. — Psilocybin therapy is associated with relaxed and revised negative self-beliefs that lead to acute neural entropy, according to a presenter at the American Society of Clinical Psychopharmacology annual meeting.

“Psychedelics are a range of pharmacological agents,” Richard J. Zeifman, PhD, postdoctoral fellow at the NYU Langone Health Center for Psychedelic Medicine, said in his presentation. “They produce a range of effects on consciousness, changes in cognition, pathways of perception as well as changes in one’s sense of self.”

Zeifman and colleagues carried out a preliminary examination of the efficacy of psychedelic therapy under the Relaxed Beliefs Under pSychedelics (REBUS) model, which posits that psychedelics which target serotonic regions of the brain decrease certain neurobiologically encoded beliefs.

Their study assessed two main psychological assumptions of REBUS: that psychedelics foster acute relaxation and post-acute revision of confidence in mental-health-relevant beliefs, which in turn facilitate positive therapeutic outcomes and are associated with the entropy of EEG signals.

Eleven healthy participants were administered both a low dose (1 mg) and high dose (25 mg) of psilocybin 4 weeks apart. Confidence ratings for personal beliefs were obtained before, during, and 4-weeks post-psilocybin administration via the Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS) as well as the Relaxed Beliefs Questionnaire (REB-Q). Acute entropy and subjective experiences were measured at 1, 2 and 4.5 hours post dose, as was well-being before and 4 weeks after administration.

The researchers found that confidence in negative self-beliefs decreased after the administration of 25 mg psilocybin. Entropy under 25 mg psilocybin was correlated with decreases in negative self-belief confidence both acutely and at the 4-week follow-up.

Zeifman and colleagues additionally discovered strong causal evidence between decreases in negative self-belief confidence and increases in well-being, the first evidence that relaxation and revision of negative self-belief confidence mediates psilocybin's positive psychological outcomes. They added that “tentative” evidence was found for increased neuronal entropy.

“Preliminary results suggest that even a little bit of psilocybin makes patients relaxed,” Zeifman said. “And we also found that generally both relaxation and revision was associated with acute neuro entropy and positive therapeutic outcomes.”