Dreamlike effects of LSD on waking imagery in humans depend on serotonin 2A receptor activation
Rainer Kraehenmann, Dan Pokorný, Leonie Vollenweider, Katrin H. Preller, Thomas Pokorny, Erich Seifritz, Franz X. Vollenweider
Psychopharmacology July 1, 2017 DOI: 10.1007/s00213-017-4610-0 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Within-subjects experimental study Peer reviewed |
|---|---|
| Sample size | 25 |
| Population | Healthy subjects |
| Interventions | LSD Ketanserin |
| Dose | 100 mcg LSD orally, 40 mg ketanserin orally |
| Duration | 7 hours after drug administration |
| Topics | LSD Serotonin |
| Keywords | Ketanserin Guided mental imagery Dreams Cognitive bizarreness Healthy subjects Visual hallucinations |
| Key findings | LSD increases cognitive bizarreness in guided mental imagery, an effect fully blocked by the 5-HT2A receptor antagonist ketanserin and correlated with loss of self-boundaries and cognitive control. |
Abstract
Rationale: Accumulating evidence indicates that the mixed serotonin and dopamine receptor agonist lysergic acid diethylamide (LSD) induces an altered state of consciousness that resembles dreaming.
Objectives: This study aimed to test the hypotheses that LSD produces dreamlike waking imagery and that this imagery depends on 5-HT2A receptor activation and is related to subjective drug effects.
Methods: Twenty-five healthy subjects performed an audiorecorded guided mental imagery task 7 h after drug administration during three drug conditions: placebo, LSD (100 mcg orally) and LSD together with the 5-HT2A receptor antagonist ketanserin (40 mg orally). Cognitive bizarreness of guided mental imagery reports was quantified as a standardised formal measure of dream mentation. State of consciousness was evaluated using the Altered State of Consciousness (5D-ASC) questionnaire.
Results: LSD, compared with placebo, significantly increased cognitive bizarreness ( p < 0.001). The LSD-induced increase in cognitive bizarreness was positively correlated with the LSD-induced loss of self-boundaries and cognitive control ( p < 0.05). Both LSD-induced increases in cognitive bizarreness and changes in state of consciousness were fully blocked by ketanserin.
Conclusions: LSD produced mental imagery similar to dreaming, primarily via activation of the 5-HT2A receptor and in relation to loss of self-boundaries and cognitive control. Future psychopharmacological studies should assess the differential contribution of the D2/D1 and 5-HT1A receptors to cognitive bizarreness.
Comparable studies
Other experimental studies on LSD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Neural correlates of the LSD experience revealed by multimodal neuroimaging. Human participants | 2016 | Experimental study | |
| Crystal structure of an LSD-bound human serotonin receptor | 2017 | Experimental study with structural biology and molecular dynamics simulations | |
| Lysergic Acid Diethylamide: Sensitive Neuronal Units in the Midbrain Raphe Midbrain neurons containing serotonin | 1968 | Experimental study | |
| Connectome-harmonic decomposition of human brain activity reveals dynamical repertoire re-organization under LSD. Human brain | 2017 | Experimental study | |
| LSD-Assisted Psychotherapy in Patients with Terminal Cancer Cancer patients | 1973 | Experimental study | n = 60 |
Citations in the library
Cited by 131
- Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern‐era clinical studies Acta Psychiatrica Scandinavica October 30, 2020
- Correlation between the potency of hallucinogens in the mouse head-twitch response assay and their behavioral and subjective effects in other species. Neuropharmacology May 1, 2020
- Designer drugs: mechanism of action and adverse effects Archives of Toxicology April 1, 2020
- Acute dose-dependent effects of lysergic acid diethylamide in a double-blind placebo-controlled study in healthy subjects Neuropsychopharmacology October 15, 2020
- Modern Clinical Research on LSD Neuropsychopharmacology April 27, 2017
and 126 more in the library
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- Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies Journal of Psychopharmacology September 20, 2010
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