SynthesisThe international journal of neuropsychopharmacology2020
Psychosis-Relevant Effects of Intravenous Delta-9-Tetrahydrocannabinol: A Mega Analysis of Individual Participant-Data from Human Laboratory Studies.
Synthesis in The international journal of neuropsychopharmacology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 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
18 citing papers in PubMed, 40 citations in OpenAlex.
- Randomized Laboratory Study of Single-Dose Cannabis, Dronabinol, and Placebo in Patients With Schizophrenia and Cannabis Use Disorder.Schizophrenia bulletin · 2025Trial
- Delta-9-Tetrahydrocannabinol, Cannabidiol, and Acute Psychotomimetic States: A Balancing Act of the Principal Phyto-Cannabinoids on Human Brain and Behavior.Cannabis and cannabinoid research · 2023Trial
- Preliminary study of the interactive effects of THC and ethanol on self-reported ability and simulated driving, subjective effects, and cardiovascular responses.Psychopharmacology · 2023Trial
- [Psychiatric aspects of commercially available products containing cannabidiol].Der Nervenarzt · 2026Review
- Substance Use Disorders and the Psychosis Spectrum: Assessment, Clinical Challenges and Management.Journal of clinical medicine · 2026Review
- Authors' response to the commentary, "Cannabis and psychopathology: A 2024 snapshot - Examining the complexities of diagnostic stability in cannabis-induced psychosis".Indian journal of psychiatry · 2025Article
- Exploring causal mechanisms of psychosis risk.Neuroscience and biobehavioral reviews · 2024Review
- Development and initial validation of the cannabis-related psychosis risk literacy scale (CPRL): a multinational psychometric study.BMC psychiatry · 2024Article
- Assessing rates and predictors of cannabis-associated psychotic symptoms across observational, experimental and medical research.Nature. Mental health · 2024Article
- Understanding the Mechanisms of Action and Effects of Drugs of Abuse.Molecules (Basel, Switzerland) · 2023Review
- Rates and correlates of cannabis-associated psychotic symptoms in over 230,000 people who use cannabis.Translational psychiatry · 2022Article
- Associations Between Canada's Cannabis Legalization and Emergency Department Presentations for Transient Cannabis-Induced Psychosis and Schizophrenia Conditions: Ontario and Alberta, 2015-2019.Canadian journal of psychiatry. Revue canadienne de psychiatrie · 2022Article
- Higher Risk, Higher Reward? Self-Reported Effects of Real-World Cannabis Use in Parkinson's Disease.Movement disorders clinical practice · 2022Article
- Editorial: Gone to Pot: Examining the Association Between Cannabis Use and Medical/Psychiatric Disorders.Frontiers in psychiatry · 2022Article
- Changes in Expression of DNA-Methyltransferase and Cannabinoid Receptor mRNAs in Blood Lymphocytes After Acute Cannabis Smoking.Frontiers in psychiatry · 2022Article
- Review of the Endocannabinoid System.Biological psychiatry. Cognitive neuroscience and neuroimaging · 2021Review
- Cannabis Use, Cannabis Use Disorder, and Comorbid Psychiatric Illness: A Narrative Review.Journal of clinical medicine · 2020Review
- Cannabis and Psychosis: Weeding Out Fact from Fiction.Missouri medicineArticle
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 1 institution in 1 country.
Funding
Abstract
introductionThere is increasing interest in the relationship between cannabinoids and psychosis. While individual human laboratory studies have been critical in demonstrating that cannabinoids (e.g., delta-9-tetrahydrocannabinol [THC]) can induce acute transient psychosis-like effects in healthy human volunteers, combining data from multiple studies offers a fine-grained view of these effects.
methodsTHC-induced psychosis-relevant effects were examined using a data repository of 10 double-blind, randomized, placebo-controlled, crossover studies with 400 i.v. THC infusions in healthy human volunteers. The Positive and Negative Syndrome scale was used to measure psychotomimetic effects. The profile of symptoms, frequency of a response, its relationship to THC dose and substance use, latent structure in Positive and Negative Syndrome scale response, and the relationships between psychotomimetic and perceptual alteration symptoms were evaluated.
resultsClinically meaningful increases in positive symptoms were noted in 44.75% infusions; conceptual disorganization, hallucinations, blunted affect, somatic concern, motor retardation, and poor attention were the items most frequently altered by THC. The increase in Positive and Negative Syndrome scale positive symptoms was positively associated with THC dose (beta = 11.13, SE = 4.94, Wald χ 2 = 19.88, P < .001) and negatively associated with frequent cannabis use (beta = -0.575, SE = 0.14, Wald χ 2 = 18.13, P < .001). Furthermore, positive symptoms were strongly correlated with Clinician Administered Dissociative States Scale perceptual alterations score (rs = 0.514, P < .001).
conclusionIntravenous administration of THC consistently induces psychotomimetic effects that include symptoms across Positive and Negative Syndrome scale domains. Moreover, healthy individuals who frequently use cannabis have a blunted psychotomimetic response.
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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.