Psychedelic experience dose-dependently modulated by cannabis: results of a prospective online survey
In a prospective online survey of 321 people, concomitant cannabis use during a serotonergic psychedelic experience was associated with dose-dependent increases in acute subjective effects — linear increases in mystical experiences, visual phenomena and ego dissolution, and a quadratic increase in challenging experiences, with no effect on emotional breakthrough. However, the observational design and self-report measures limit causal inference and the clinical implications of these interactions.
Authors
- Fernando Rosas
- Robin Carhart-Harris
- David Nutt
Published
Abstract
Rationale. Classic psychedelics are currently being studied as novel treatments for a range of psychiatric disorders. However, research on how psychedelics interact with other psychoactive substances remains scarce.
Objectives
The current study aimed to explore the subjective effects of psychedelics when used alongside cannabis.
Methods
Participants (n = 321) completed a set of online surveys at 2 time points: 7 days before, and 1 day after a planned experience with a serotonergic psychedelic. The collected data included demographics, environmental factors (so-called setting) and five validated questionnaires: Mystical Experience Questionnaire (MEQ), visual subscales of Altered States of Consciousness Questionnaire (ASC-Vis), Challenging Experience Questionnaire (CEQ), Ego Dissolution Inventory (EDI) and Emotional Breakthrough Inventory (EBI). Participants were grouped according to whether they had reported using no cannabis (n = 195) or low (n = 53), medium (n = 45) or high (n = 28) dose, directly concomitant with the psychedelic. Multivariate analysis of covariance (MANCOVA) and contrasts was used to analyse differences in subjective effects between groups while controlling for potential confounding contextual ‘setting’ variables.
Results
The simultaneous use of cannabis together with classic serotonergic psychedelics was associated with more intense psychedelic experience across a range of measures: a linear relationship was found between dose and MEQ, ASC-Vis and EDI scores, while a quadratic relationship was found for CEQ scores. No relationship was found between the dose of cannabis and the EBI.
Conclusions
Results imply a possible interaction between the cannabis and psychedelic on acute subjective experiences; however, design limitations hamper our ability to draw firm inferences on directions of causality and the clinical implications of any such interactions.
Research Summary of 'Psychedelic experience dose-dependently modulated by cannabis: results of a prospective online survey'
Introduction
Classic serotonergic psychedelics are receiving renewed attention as adjuncts to psychotherapy for a range of psychiatric conditions, and acute subjective effects—such as perceptual alterations, intensified emotion, mystical-type experiences and ego-dissolution—are thought to mediate therapeutic benefit. Beyond psychedelic dose, non-pharmacological factors commonly labelled 'set' (mindset, expectations) and 'setting' (environmental context) influence the character and intensity of these experiences. Despite increasing clinical interest, little quantitative research has examined how psychedelics interact acutely with other psychoactive drugs in naturalistic use. Kuc and colleagues aimed to address this gap by examining whether concomitant cannabis use modulates the subjective quality of a serotonergic psychedelic experience. The study sought to quantify associations between self-reported cannabis dose taken alongside a psychedelic and scores on validated measures of mystical experience, visual alterations, challenging experiences, ego dissolution and emotional breakthrough, while attempting to account for contextual confounders such as aspects of setting and guiding framework.
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Study Details
- Study Typeindividual
- Journal
- Compound
- Topic
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- APA Citation
Kuc, J., Kettner, H., Rosas, F., Erritzoe, D., Haijen, E., Kaelen, M., Nutt, D., & Carhart-Harris, R. L. (2022). Psychedelic experience dose-dependently modulated by cannabis: results of a prospective online survey. Psychopharmacology, 239(5), 1425-1440. https://doi.org/10.1007/s00213-021-05999-1
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