Department of Medical Psychology and Psychiatry, School of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo 126, Cidade Universitária Zeferino Vaz, Campinas, São Paulo, 13083-887, Brazil.
Interdisciplinary Cooperation for Ayahuasca Research and Outreach (ICARO), School of Medical Sciences, University of Campinas, Campinas, São Paulo, Brazil.
Psychopharmacology (Berl). 2022 Jun;239(6):1721-1733. doi: 10.1007/s00213-021-06006-3. Epub 2021 Oct 28.
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.
To elucidate the effects of LSD on the stream of thought.
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.
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).
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.
思维流描述了思维自由漫游时的本质，是一种连续且高度动态的精神状态，如在思维漫游或自由联想中。经典的血清素能致幻剂已知会深刻影响感知、认知和语言，但它们对思维流的影响在很大程度上仍未得到探索。
阐明 LSD 对思维流的影响。
在一项随机、双盲、安慰剂对照、交叉研究中，24 名健康参与者分别接受 50μg 麦角酸二乙酰胺（LSD）或无效安慰剂。通过阿姆斯特丹静息状态问卷（ARSQ）测量思维漫游，通过前向流动任务（FFT）测量三种种子词类型（动物、物体、抽象词）的自由联想。ARSQ 和 FFT 分别在给药后+0 h、+2 h、+4 h、+6 h、+8 h 和+24 h 进行评估。
与安慰剂相比，LSD 诱导了我们概念化为“混乱”（思维不连续、嗜睡减少、计划、思维受控制、工作思维和过去思维）、“意义”（深入思考、不分享想法）和“感觉”（气味思考、声音思考）的不同方面的思维漫游。LSD 增加了自由联想下抽象词的 FFT，反映了“抽象流”。总体而言，混乱在+2 h 到+6 h 之间最为明显，其次是意义（+2 h 到+4 h）、感觉（+2 h）和抽象流（+4 h）。
LSD 影响思维流的几个层面（主动、被动）、方面（混乱、意义、感觉、抽象）和时间点（从+2 h 到+6 h）。+4 h 时混乱、意义和抽象流的增加表明在精神分析治疗中有一个晚期治疗窗口的效用。
