The effects of microdose LSD on time perception: a randomised, double-blind, placebo-controlled trial

Abstract

Rationale Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness. Methods We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals. Results LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reproduction of temporal intervals of 2000 ms and longer with these effects most pronounced in the 10 μg dose condition. Hierarchical regression analyses indicated that LSD-mediated over-reproduction was independent of marginal differences in self-reported drug effects across conditions. Conclusions These results suggest that microdose LSD produces temporal dilation of suprasecond intervals in the absence of subjective alterations of consciousness.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of low dose lysergic acid diethylamide (LSD) in healthy older volunteers

“…These results are consistent with recent findings that cognition was unaffected after acute dosing of 6.5 μg, 13 μg, and 26 μg LSD in healthy participants (Bershad et al 2019). In a previous study presenting other PD results from the current trial, Yanakieva et al (2018) argue that temporal dilation of suprasecond intervals observed under microdoses of LSD may be the result of a disruption of cognitive functions such as working memory and attention. CANTAB tests used in this study, PAL, SWM, and RVP, measure visual memory, spatial working memory, and visual attention, respectively.…”

“…A subset of results from this study was published separately, from a task exploring the effects of 5 μg, 10 μg, and 20 μg of LSD on time perception (Yanakieva et al 2018). Ratings on a regularly completed subjective drug effects questionnaire were used to investigate any impact of peak times of selfperceived drug effects on interval timing.…”

Experimentally induced awe does not affect implicit and explicit time perception

“…Indeed it has been found for instance that extended practice with mindfulness meditation results in a leftward shift in the temporal bisection function, indicating a lengthening of perceived time (Droit-Volet, Fanget, & Dambrun, 2015;Kramer, Weger, & Sharma, 2013). Other studies have shown that both high and micro-doses of LSD, result in an overestimation of time, e.g., as measured by using a temporal reproduction task (Liechti, Dolder, & Schmid, 2017;Yanakieva et al, 2018). Thus, studying the changes in both implicit and explicit time perception in association with self-transcendent experiences seems to be a promising area of research.…”

A Systematic Study of Microdosing Psychedelics

“…Third, a large cross sectional study found that microdosers reported reduced levels of negative attitudes and emotions, and increased wisdom, open-mindedness and creativity, relative to people who had never microdosed (T. Anderson et al, 2018). The most scientifically rigorous study to date, was a double blind placebo controlled study by Yanakieva et al (2018). This study showed changes in time perception following microdosing, but did not investigate variables related to health or wellbeing.…”

“…Participation in these communities may lead to specific expectations that shape individuals' experiences of microdosing. Most of the early research on microdosing has not included a control group or explicitly investigated participant expectations (although see Yanakieva et al, 2018 Procedure. As a way of indexing participants' expectations about the effects of microdosing we generated a new scale, consisting of items that related to each of the subscales analysed in Study One.…”