Healthy VolunteersNeuroimaging & Brain MeasuresLSD

Increased thalamic resting state connectivity as a core driver of LSD-induced hallucinations

Following oral administration of 100 μg LSD to 20 healthy participants, resting‑state fMRI showed increased thalamic functional connectivity to multiple cortical regions, with thalamus–right fusiform and thalamus–insula connectivity correlating with subjective visual and auditory effects. These findings suggest enhanced thalamocortical coupling—likely via 5‑HT2A receptor mechanisms—may underlie LSD‑induced hallucinations by facilitating cortical excitability.

Authors

  • Stefan Borgwardt
  • Patrick Dolder
  • Matthias Liechti

Published

Acta Psychiatrica Scandinavica
individual Study

Abstract

Objective

It has been proposed that the thalamocortical system is an important site of action of hallucinogenic drugs and an essential component of the neural correlates of consciousness. Hallucinogenic drugs such as LSD can be used to induce profoundly altered states of consciousness, and it is thus of interest to test the effects of these drugs on this system.Method100 μg LSD was administrated orally to 20 healthy participants prior to fMRI assessment. Whole brain thalamic functional connectivity was measured using ROI‐to‐ROI and ROI‐to‐voxel approaches. Correlation analyses were used to explore relationships between thalamic connectivity to regions involved in auditory and visual hallucinations and subjective ratings on auditory and visual drug effects.

Results

LSD caused significant alterations in all dimensions of the 5D‐ASC scale and significantly increased thalamic functional connectivity to various cortical regions. Furthermore, LSD‐induced functional connectivity measures between the thalamus and the right fusiform gyrus and insula correlated significantly with subjective auditory and visual drug effects.

Conclusion

Hallucinogenic drug effects might be provoked by facilitations of cortical excitability via thalamocortical interactions. Our findings have implications for the understanding of the mechanism of action of hallucinogenic drugs and provide further insight into the role of the 5‐HT2A‐receptor in altered states of consciousness.

Available with Blossom Pro

Research Summary of 'Increased thalamic resting state connectivity as a core driver of LSD-induced hallucinations'

Introduction

Hallucinogenic drugs produce distinctive alterations in perception, cognition and emotion, and understanding their neural correlates may illuminate mechanisms of altered consciousness. Prior models and empirical work have implicated the thalamus as an important site of action for hallucinogens: one influential idea is that hallucinogens disrupt thalamic gating of internal and external signals, permitting increased passage of information to cortex. Neuroimaging studies have reported mixed effects of hallucinogens on thalamic metabolism and blood flow, and some recent resting-state fMRI work has suggested increased thalamocortical functional connectivity after psilocybin or LSD, but these findings had not been investigated in detail. This study tested the acute effects of a single oral dose of LSD (100 µg) on thalamic resting-state functional connectivity (rFC) in healthy volunteers using a placebo-controlled, double-blind cross-over design. The investigators hypothesised that LSD would increase thalamocortical connectivity relative to placebo and that those connectivity changes would relate to subjective LSD-induced visual and auditory alterations measured with the 5D-ASC questionnaire. The work aims to clarify whether altered thalamocortical interactions are a core neural correlate of LSD-induced hallucinations and altered consciousness.

Expert Research Summaries

Go Pro to access AI-powered section-by-section summaries, editorial takes, and the full research toolkit.

Full Text PDF

Full Paper PDF

Create a free account to open full-text PDFs.

Study Details

References (17)

Papers cited by this study that are also in Blossom

Acute effects of lysergic acid diethylamide in healthy subjects

Schmid, Y., Enzler, F., Gasser, P. et al. · Biological Psychiatry (2015)

The paradoxical psychological effects of lysergic acid diethylamide (LSD)

Carhart-Harris, R. L., Kaelen, M., Bolstridge, M. et al. · Psychological Medicine (2016)

253 cited
Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer

Grob, C. S., Danforth, A. L., Chopra, G. S. et al. · JAMA Psychiatry (2011)

Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study

Carhart-Harris, R. L., Bolstridge, M., Rucker, J. et al. · Lancet Psychiatry (2016)

1174 cited
LSD acutely impairs fear recognition and enhances emotional empathy and sociality

Dolder, P. C., Schmid, Y., Müller, F. et al. · Neuropsychopharmacology (2016)

Serotonin research: contributions to understanding psychoses

Geyer, M. A., Vollenweider, F. X. · Trends in Pharmacological Sciences (2008)

Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin

Carhart-Harris, R. L., Erritzoe, D., Williams, T. et al. · PNAS (2012)

Psilocybin induces schizophrenia-like psychosis in humans via a serotonin-2 agonist action

Vollenweider, F. X., Vollenweider-Scherpenhuyzen, M. F. I., Bäbler, A. et al. · NeuroReport (1998)

Show all 17 references
The fabric of meaning and subjective effects in LSD-induced states depend on serotonin 2A receptor activation

Preller, K. H., Herdener, M., Pokorny, T. et al. · Current Biology (2017)

Functional connectivity measures after psilocybin inform a novel hypothesis of early psychosis

Carhart-Harris, R. L., Leech, R., Erritzoe, D. et al. · Schizophrenia Bulletin (2012)

241 cited
Increased global functional connectivity correlates with LSD-induced ego dissolution

Tagliazucchi, E., Roseman, L., Kaelen, M. et al. · Current Biology (2016)

Pharmacokinetics and concentration-effect relationship of oral LSD in humans

Dolder, P. C., Schmid, Y., Haschke, M. et al. · International Journal of Neuropsychopharmacology (2015)

97 cited
Psychometric evaluation of the altered states of consciousness rating scale (OAV)

Studerus, E., Gamma, A., Vollenweider, F. X. · PLOS ONE (2010)

Alterations of consciousness and mystical-type experiences after acute LSD in humans

Liechti, M. E., Dolder, P. C., Schmid, Y. · Psychopharmacology (2016)

190 cited
Neural correlates of the LSD experience revealed by multimodal neuroimaging

Carhart-Harris, R. L., Muthukumaraswamy, S., Roseman, L. et al. · PNAS (2016)

Cited By (52)

Papers in Blossom that reference this study

Molecular, haemodynamic, and functional effects of LSD in the human brain

McCulloch, D. E-W., Larsen, K., Johansen, A. et al. · MedRvix (2025)

Effective-connectivity of thalamocortical interactions following d-amphetamine, LSD, and MDMA administration

Avram, M., Müller, F., Preller, K. H. et al. · Biological Psychiatry (2024)

13 cited
Visual hallucinations originating in the retinofugal pathway under clinical and psychedelic conditions

Tipado, Z., Kuypers, K. P. C., Sorger, B. et al. · European Neuropsychopharmacology (2024)

Psychedelics for acquired brain injury: a review of molecular mechanisms and therapeutic potential

Allen, J., Dames, S., Foldi, C. J. et al. · Molecular Psychiatry (2024)

LSD-induced changes in the functional connectivity of distinct thalamic nuclei

Pizzi, S. D., Chiacchiaretta, P., Sestieri, C. et al. · NeuroImage (2023)

9 cited
Dose-response relationships of LSD-induced subjective experiences in humans

Prugger, J., Hirschfeld, T., Majic, T. et al. · Neuropsychopharmacology (2023)

19 cited
A complex systems perspective on psychedelic brain action

Girn, M., Rosas, F. E., Daws, R. E. et al. · Trends in Cognitive Sciences (2023)

Show all 52 papers
LSD-induced increase of Ising temperature and algorithmic complexity of brain dynamics

Ruffini, G., Damiani, G., Lozano-Soldevilla, D. et al. · PLOS ONE (2023)

The Altered States Database: Psychometric data from a systematic literature review

Prugger, J., Derdiyok, E., Dinkelacker, J. et al. · Scientific Data (2022)

The effect of lysergic acid diethylamide (LSD) on whole-brain functional and effective connectivity

Bedford, P., Hauke, D. J., Wang, Z. et al. · Neuropsychopharmacology (2022)

Low doses of lysergic acid diethylamide (LSD) increase reward-related brain activity

Glazer', J., Murray, C. H., Nusslock', R. et al. · Neuropsychopharmacology (2022)

Scoping Review of Experiential Measures from Psychedelic Research and Clinical Trials

Herrmann, Z., Earleywine, M., De Leo, J. et al. · Journal of Psychoactive Drugs (2022)

Neural Mechanisms and Psychology of Psychedelic Ego Dissolution

Stoliker, D., Egan, G. F., Friston, K. J. et al. · Pharmacological Reviews (2022)

Psychedelic Resting-state Neuroimaging: A Review and Perspective on Balancing Replication and Novel Analyses

McCulloch, D. E-W., Knudsen, G. M., Barrett, F. S. et al. · Neuroscience and Biobehavioral Reviews (2022)

Differential contributions of serotonergic and dopaminergic functional connectivity to the phenomenology of LSD

Lawn, T., Dipasquale, O., Vamvakas, A. et al. · Psychopharmacology (2022)

40 cited
Evaluating the Potential Use of Serotonergic Psychedelics in Autism Spectrum Disorder

Markopoulos, A., Inserra, A., De Gregorio, D. et al. · Frontiers in Pharmacology (2022)

30 cited
Classic Psychedelic Drugs: Update on Biological Mechanisms

Vollenweider, F. X., Smallridge, J. W. · Pharmacopsychiatry (2022)

71 cited
Models of psychedelic drug action: modulation of cortical-subcortical circuits

Doss, M. K., Madden, M. B., Gaddis, A. et al. · Brain (2021)

Bridging the Gap? Altered Thalamocortical Connectivity in Psychotic and Psychedelic States

Avram, M., Rogg, H., Korda, A. et al. · Frontiers in Psychiatry (2021)

35 cited
Improving cognitive functioning in major depressive disorder with psychedelics: a dimensional approach

Kuiperes, Z., Schreiber, R. · Neurobiology of Learning and Memory (2021)

Psilocybin-induced changes in brain network integrity and segregation correlate with plasma psilocin level and psychedelic experience

Madsen, M. K., Stenbaek, D. S., Arvidsson, A. et al. · European Neuropsychopharmacology (2021)

Trips and Neurotransmitters: Discovering Principled Patterns across 6,850 Hallucinogenic Experiences

Ballentine, G., Friedman, S. F., Bzdok, D. · Science Advances (2021)

44 cited
Role of the 5-HT2A receptor in acute effects of LSD on empathy and circulating oxytocin

Holze, F., Avedisian, I., Varghese, N. et al. · Frontiers in Pharmacology (2021)

Psychedelics and Consciousness: Distinctions, Demarcations, and Opportunities

Yaden, D. B., Johnson, M. W., Griffiths, R. R. et al. · International Journal of Neuropsychopharmacology (2021)

Increased sensitivity to strong perturbations in a whole-brain model of LSD

Jobst, B. M., Atasoy, S., Ponce-Alvarez, A. et al. · NeuroImage (2021)

Psilocin acutely disrupts sleep and affects local but not global sleep homeostasis in laboratory mice

Thomas, C. W., Blanco-Duque, C., Breant, B. et al. · Translational Psychiatry (2021)

The History of Psychedelics in Psychiatry

Nichols, D. E., Walter, H. · Pharmacopsychiatry (2020)

Psychedelic drugs: neurobiology and potential for treatment of psychiatric disorders

Vollenweider, F. X., Preller, K. H. · Nature Reviews Neuroscience (2020)

Decreased directed functional connectivity in the psychedelic state

Barnett, L., Muthukumaraswamy, S., Carhart-Harris, R. L. · NeuroImage (2020)

Preliminary report on the effects of a low dose of LSD on resting-state amygdala functional connectivity

Bershad, A. K., Preller, K. H., Lee, R. et al. · Biological Psychiatry (2020)

88 cited
Psychedelics and Psychedelic-Assisted Psychotherapy

Reiff, C. M., Richman, E. E., Nemeroff, C. B. et al. · American Journal of Psychiatry (2020)

Acute Subjective and Behavioral Effects of Microdoses of Lysergic Acid Diethylamide in Healthy Human Volunteers

Bershad, A. K., Schepers, S. T., Bremmer, M. P. et al. · Biological Psychiatry (2019)

Acute effects of lysergic acid diethylamide (LSD) on resting brain function

Felix, M., Stefan, B. · Swiss Medical Weekly (2019)

REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics

Carhart-Harris, R. L., Friston, K. J. · Pharmacological Reviews (2019)

Pharmacokinetics and subjective effects of a novel oral LSD formulation in healthy subjects

Holze, F., Duthaler, U., Vizeli, P. et al. · British Journal of Clinical Pharmacology (2019)

Effective connectivity changes in LSD-induced altered states of consciousness in humans

Preller, K. H., Razi, A., Zeidman, P. et al. · PNAS (2019)

Psychedelics, meditation, and self-consciousness

Milliere, R., Carhart-Harris, R. L., Roseman, L. et al. · Frontiers in Psychology (2018)

Dark Classics in Chemical Neuroscience: Mescaline

Cassels, B. K., Sáez-Briones, P. · ACS Chemical Neuroscience (2018)

The entropic brain - revisited

Carhart-Harris, R. L. · Neuropharmacology (2018)

Dark Classics in Chemical Neuroscience: Lysergic Acid Diethylamide (LSD)

Nichols, D. E. · ACS Chemical Neuroscience (2018)

Altered network hub connectivity after acute LSD administration

Müller, F., Dolder, P. C., Schmidt, A. et al. · NeuroImage (2018)

142 cited
Modern clinical research on LSD

Liechti, M. E. · Neuropsychopharmacology (2017)

Your Personal Research Library

Go Pro to save papers, add notes, rate studies, and organize your research into custom shelves.