Trial reportCNS drugs2024
Oral Delta-9-Tetrahydrocannabinol (THC) Increases Parasympathetic Activity and Supraspinal Conditioned Pain Modulation in Chronic Neuropathic Pain Male Patients: A Crossover, Double-Blind, Placebo-Controlled Trial.
Trial report in CNS drugs, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT02560545 (Cannabinoids Effects on the Pain Modulation System), which is not on this map. Cited by 9 papers, 1 of them a synthesis that pooled it.
What it found
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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.
Cannabinoids Effects on the Pain Modulation System
Who cites it
9 citing papers in PubMed, 1 synthesis or guideline pooled it, 14 citations in OpenAlex.
- Are Cannabis-Based Medicines a Useful Treatment for Neuropathic Pain? A Systematic Review.Biomolecules · 2025Pooled it
- An opioid-withholding human laboratory paradigm during opioid agonist treatment for opioid use disorder and chronic pain: Phase- and dose-dependent effects of cannabidiol.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2026Trial
- Delta-9-tetrahydrocannabinol and Cannabidiol for Pain: Preclinical and Clinical Models.Current topics in behavioral neurosciences · 2026Review
- The impact of tetrahydrocannabinol on central pain modulation in chronic pain: a randomized clinical comparative study of offset analgesia and conditioned pain modulation in fibromyalgia.Journal of cannabis research · 2025Article
- Cannabinoids in neuropathic pain treatment: pharmacological insights and clinical outcomes from recent trials.Naunyn-Schmiedeberg's archives of pharmacology · 2025Review
- Effects of intravenous d9-THC on pupillary reaction and pupil size: a prospective, placebo-controlled trial in healthy volunteers not regularly consuming cannabis.BMC ophthalmology · 2025Article
- Review
- Review
- Chemotherapy-Induced Peripheral Neuropathy: A Recent Update on Pathophysiology and Treatment.Life (Basel, Switzerland) · 2024Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundDisordered autonomic nervous system regulation and supraspinal pain inhibition have been repeatedly described in chronic pain. We aimed to explore the effects of δ-9-tetrahydrocannabinol (THC), an emerging treatment option, on autonomic nervous system and central pain modulation measures in patients with chronic pain.
methodsTwelve male patients with chronic radicular neuropathic pain participated in a randomized, double-blind, crossover, placebo-controlled, single-administration trial. Low/high frequency (LF/HF) heart rate variability (HRV) ratio and conditioned pain modulation (CPM) response were measured and resting-state functional magnetic resonance imaging (MRI) was performed at baseline and after sublingual administration of either 0.2 mg/kg oral THC or placebo.
resultsTHC significantly reduced the LF/HF ratio compared with placebo (interaction effect F(1,11) = 20.5; p < 0.005) and significantly improved CPM responses (interaction effect F(1,9) = 5.2; p = 0.048). The THC-induced reduction in LF/HF ratio correlated with increased functional connectivity between the rostral ventrolateral medulla and the dorsolateral prefrontal cortex [T(10) = 6.4, cluster p-FDR < 0.005].
conclusionsTHC shifts the autonomic balance towards increased parasympathetic tone and improves inhibitory pain mechanisms in chronic pain. The increase in vagal tone correlates with connectivity changes in higher-order regulatory brain regions, suggesting THC exerts top-down effects. These changes may reflect a normalizing effect of THC on multiple domains of supraspinal pain dysregulation. CLINICAL TRIAL REGISTRY NUMBER: NCT02560545.
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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.