Acute effects of LSD on amygdala activity during processing of fearful stimuli in healthy subjects

This double-blind, randomized, crossover study (n=20) investigated the effects of LSD (100 μg) on brain activity while participants were shown fearful facial stimuli and found that LSD decreased amygdala reactivity, a brain region that mediates emotional processing.

Abstract

Introduction: Lysergic acid diethylamide (LSD) induces profound changes in various mental domains, including perception, self-awareness and emotions.

Methods: We used functional magnetic resonance imaging (fMRI) to investigate the acute effects of LSD on the neural substrate of emotional processing in humans. Using a double-blind, randomised, cross-over study design, placebo or 100 μg LSD were orally administered to 20 healthy subjects before the fMRI scan, taking into account the subjective and pharmacological peak effects of LSD. The plasma levels of LSD were determined immediately before and after the scan. The study (including the a priori-defined study end point) was registered at ClinicalTrials.gov before study start (NCT02308969).

Results: The administration of LSD reduced reactivity of the left amygdala and the right medial prefrontal cortex relative to placebo during the presentation of fearful faces (P<0.05, family-wise error). Notably, there was a significant negative correlation between LSD-induced amygdala response to fearful stimuli and the LSD-induced subjective drug effects (P<0.05).

Discussion: These data suggest that acute administration of LSD modulates the engagement of brain regions that mediate emotional processing.”

Authors: Felix Muller, Claudia Lenz, Patrick C. Dolder, S. Harder, Yasmin Schmid, Undine E. Lang, Matthias E. Liechti & Stefan Borgwardt

Study details

Compounds studied
LSD

Topics studied
Neuroscience

Study characteristics
Double-Blind Randomized

Participants
20 Humans

Authors

Authors associated with this publication with profiles on Blossom

Felix Müller
Felix Müller is a researcher at the University of Basel. He is leading the research project on psychedelics at the Department of Psychiatry.

Yasmin Schmid
Yasmin Schmid is a physician who previously worked at the University of Basil Liechti Lab.

Matthias Liechti
Matthias Emanuel Liechti is the research group leader at the Liechti Lab at the University of Basel.

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