Low-dose LSD and the stream of thought: Increased Discontinuity of Mind, Deep Thoughts and abstract flow

In this double-blind randomized controlled trial (n=24) healthy participants were given 50μg of LSD to determine the effects of LSD on the stream of thought. It was found that LSD similarly affected the passive and active stream of thought towards deviant but meaningful thought patterns with increased chaos and meaning during mind-wandering and abstract flow during free association.

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.

Authors: Isabel Wießner, Marcelo Falchi, Fernanda Palhano-Fontes, Lucas Oliveira Maia, Amanda Feilding, Sidarta Ribeiro, Natália Bezerra, Draulio B. Araujo, Luís F. Tófoli