Trial reportNeuropsychopharmacology : official publication of the American College of Neuropsychopharmacology2024
Neural complexity is increased after low doses of LSD, but not moderate to high doses of oral THC or methamphetamine.
Trial report in Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
14 citing papers in PubMed, 26 citations in OpenAlex.
- Psilocybin-assisted neurofeedback for the improvement of executive functions: a randomized semi-naturalistic-lab feasibility study.Philosophical transactions of the Royal Society of London. Series B, Biological sciences · 2024Trial
- Intoxication due to Δ9-tetrahydrocannabinol is characterized by disrupted prefrontal cortex activity.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2024Trial
- The entropic brain today.Brain : a journal of neurology · 2026Review
- Multi-metric evaluations of acute psychedelic effects on fMRI brain entropy.Nature communications · 2026Article
- Characterizing non-hallucinogenic psychedelics beyond the head twitch response: phenotypic fingerprinting of lisuride and LSD.Translational psychiatry · 2026Article
- Human brain changes after first psilocybin use.Nature communications · 2026Article
- Illuminating consciousness.Frontiers in psychology · 2026Review
- On the meaning of "plasticity" in neuroscience and mental health research and its relation to the action of psychedelic therapy.Frontiers in neuroscience · 2026Article
- Addressing blinding in classic psychedelic studies with innovative active placebos.The international journal of neuropsychopharmacology · 2025Review
- LSD flattens the hierarchy of directed information flow in fast whole-brain dynamics.Imaging neuroscience (Cambridge, Mass.) · 2025Article
- Mobile EEG examination of putative biomarkers of mental health in individuals that use cannabis.NPP - digital psychiatry and neuroscience · 2025Article
- An investigation of acute physiological and psychological moderators of psychedelic-induced personality change among healthy volunteers.Neuroscience applied · 2025Article
- Is microdosing a placebo? A rapid review of low-dose LSD and psilocybin research.Journal of psychopharmacology (Oxford, England) · 2024Review
- Neural effects of psychedelics: Complexity the key word.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2024Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 2 institutions in 2 countries.
Funding
Abstract
Neural complexity correlates with one's level of consciousness. During coma, anesthesia, and sleep, complexity is reduced. During altered states, including after lysergic acid diethylamide (LSD), complexity is increased. In the present analysis, we examined whether low doses of LSD (13 and 26 µg) were sufficient to increase neural complexity in the absence of altered states of consciousness. In addition, neural complexity was assessed after doses of two other drugs that significantly altered consciousness and mood: delta-9-tetrahydrocannabinol (THC; 7.5 and 15 mg) and methamphetamine (MA; 10 and 20 mg). In three separate studies (N = 73; 21, LSD; 23, THC; 29, MA), healthy volunteers received placebo or drug in a within-subjects design over three laboratory visits. During anticipated peak drug effects, resting state electroencephalography (EEG) recorded Limpel-Ziv complexity and spectral power. LSD, but not THC or MA, dose-dependently increased neural complexity. LSD also reduced delta and theta power. THC reduced, and MA increased, alpha power, primarily in frontal regions. Neural complexity was not associated with any subjective drug effect; however, LSD-induced reductions in delta and theta were associated with elation, and THC-induced reductions in alpha were associated with altered states. These data inform relationships between neural complexity, spectral power, and subjective states, demonstrating that increased neural complexity is not necessary or sufficient for altered states of consciousness. Future studies should address whether greater complexity after low doses of LSD is related to cognitive, behavioral, or therapeutic outcomes, and further examine the role of alpha desynchronization in mediating altered states of consciousness.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.