Low-dose LSD and the stream of thought: Increased Discontinuity of Mind, Deep Thoughts and abstract flow
This randomised, double-blind, placebo-controlled crossover study (n=24) investigated the effects of LSD (50 μg) on the stream of thought in healthy participants. It finds that LSD significantly altered mind-wandering and free association by increasing facets of chaos, meaning, sensation, and abstract flow, particularly between two and six hours post-dosing.
Authors
- Luiz Tófoli
- Amanda Feilding
- Sidarta Ribeiro
Published
Abstract
Rationale
Stream of thought describes the nature of the mind when it is freely roaming, a mental state that is continuous and highly dynamic as in mind-wandering or free association. Classic serotonergic psychedelics are known to profoundly impact perception, cognition and language, yet their influence on the stream of thought remains largely unexplored.
Objective
To elucidate the effects of LSD on the stream of thought.
Methods
In a randomized, double-blind, placebo-controlled, crossover study, 24 healthy participants received 50 μg lysergic acid diethylamide (LSD) or inactive placebo. Mind-wandering was measured by the Amsterdam Resting State Questionnaire (ARSQ), free association by the Forward Flow Task (FFT) for three seed word types (animals, objects, abstract words). ARSQ and FFT were assessed at +0 h, +2 h, +4 h, +6 h, +8 h and +24 h after drug administration, respectively.
Results
LSD, compared to placebo, induced different facets of mind-wandering we conceptualized as “chaos” (Discontinuity of Mind, decreased Sleepiness, Planning, Thoughts under Control, Thoughts about Work and Thoughts about Past), “meaning” (Deep Thoughts, Not Sharing Thoughts) and “sensation” (Thoughts about Odours, Thoughts about Sounds). LSD increased the FFT for abstract words reflecting an “abstract flow” under free association. Overall, chaos was strongest pronounced (+2 h to +6 h), followed by meaning (+2 h to +4 h), sensation (+2 h) and abstract flow (+4 h).
Conclusions
LSD affects the stream of thought within several levels (active, passive), facets (chaos, meaning, sensation, abstractness) and time points (from +2 h to +6 h). Increased chaos, meaning and abstract flow at +4 h indicate the utility of a late therapeutic window in psycholytic therapy.
Research Summary of 'Low-dose LSD and the stream of thought: Increased Discontinuity of Mind, Deep Thoughts and abstract flow'
Introduction
William James' metaphor of a 'stream of thought' frames freely roaming cognition as continuous, dynamic and relatively unconstrained. The authors distinguish two modes of this stream: a passive, task-unrelated form typically labelled mind-wandering, and an active, stimulus-related form assessable by free association. Previous literature indicates that classic serotonergic psychedelics (for example LSD, psilocybin, ayahuasca) substantially alter perception, cognition and language, with anecdotal and some empirical evidence pointing to disinhibited, associative, imagery-rich and less context-bound thinking under these compounds. However, systematic, time-resolved investigations of how psychedelics affect the stream of thought—both passive and active components—have been sparse. Wießner and colleagues set out to characterise the time-dependent effects of a low dose of LSD (50 μg) on passive and active stream-of-thought processes in healthy volunteers. Specifically, the study tested two hypotheses: that LSD would alter mind-wandering during resting state and that it would increase forward flow (a measure of semantic evolution) during a chain free-association task. The authors emphasise the time course of effects, assessing multiple post-administration points to detect transient windows of altered thought and affect that could have technical and therapeutic relevance.
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Study Details
- Study Typeindividual
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- APA Citation
Wießner, I., Falchi, M., Palhano-Fontes, F., Oliveira Maia, L., Feilding, A., Ribeiro, S., Bezerra Mota, N., Araujo, D. B., & Tófoli, L. F. (2022). Low-dose LSD and the stream of thought: Increased Discontinuity of Mind, Deep Thoughts and abstract flow. Psychopharmacology, 239(6), 1721-1733. https://doi.org/10.1007/s00213-021-06006-3
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