Related Experiment Video
Updated: Jan 23, 2026

Proboscis Extension Response PER Assay in Drosophila
Published on: April 29, 2007
Replication and extension of a model predicting response to psilocybin
Suzanne L Russ1, R L Carhart-Harris2, G Maruyama3
1University of Arizona South, 1140 Columbo Ave., Sierra Vista, AZ, 85635, USA. suzanne.l.russ@gmail.com.
Background:
Recent research demonstrated the potential of psychedelic drugs as treatment for depression and death-related anxiety and as an enhancement for well-being. While generally positive, responses to psychedelic drugs can vary according to traits, setting, and mental state (set) before and during ingestion. Most earlier models explain minimal response variation, primarily related to dosage and trust, but a recent study found that states of surrender and preoccupation at the time of ingestion explained substantial variance in mystical and adverse psilocybin experiences.
Objectives:
The current study sought to replicate the previous model, extend the model with additional predictors, and examine the role of mystical experience on positive change.
Method:
A hierarchical regression model was created with crowdsourced retrospective data from 183 individuals who had self-administered psilocybin in the past year. Scales explored mental states before, during, and after psilocybin ingestion, relying on open-ended memory prompts at each juncture to trigger recollections. Controlled drug administration was not employed.
Results:
This study replicated the previous model, finding a state of surrender before ingestion a key predictor of optimal experience and preoccupation a key predictor of adverse experience. Additional predictors added to the explanatory power for optimal and adverse experience. The model supported the importance of mystical experiences to long-term change.
Conclusion:
Mental states of surrender or preoccupation at the time of ingestion explain variance in mystical or adverse psilocybin experiences, and mystical experiences relate to long-term positive change. The capacity to recognize this optimal preparatory mental state may benefit therapeutic use of psilocybin in clinical settings.
Related Concept Videos
Chromosome Replication
DNA Replication
Replication in Prokaryotes
DNA replication...
Replication in Prokaryotes
Replication in Prokaryotes
Many Proteins Work Together to Replicate the Chromosome
Replication is coordinated and carried out by a host of specialized...
Replication in Eukaryotes
The DNA Replication Fork

