Evidence map›Paper›PMID 31044290›Full record

Trial reportPsychopharmacology2019

Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition.

Thomas R Arkell, Nicholas Lintzeris, Richard C Kevin, Johannes G Ramaekers, Ryan Vandrey, Christopher Irwin, Paul S Haber, Iain S McGregor

Open access · hybridAbstract readRandomized Controlled Trial
PubMed Full text at PMC Publisher
In one paragraph

Trial report in Psychopharmacology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 90 papers, 6 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
90citing papers in PubMed, 6 pooled it
18.7field-weighted citation impact, top 1% of its field
1 · What the graph read from it

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

90 citing papers in PubMed, 6 syntheses or guidelines pooled it, 174 citations in OpenAlex.

  1. Pooled it
  2. Association of driving with blood delta-9-tetrahydrocannabinol: a systematic review.The international journal of neuropsychopharmacology · 2025
    Pooled it
  3. Does acute cannabidiol (CBD) use impair performance? A meta-analysis and comparison with placebo and delta-9-tetrahydrocannabinol (THC).Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2024
    Pooled it
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  11. Does cannabidiol make cannabis safer? A randomised, double-blind, cross-over trial of cannabis with four different CBD:THC ratios.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2023
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  12. Effect of CannEpilJournal of psychopharmacology (Oxford, England) · 2023
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  17. Identification of ∆9-tetrahydrocannabinol (THC) impairment using functional brain imaging.Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology · 2022
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30 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 4 institutions in 3 countries.

Thomas R ArkellLambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.
Nicholas LintzerisFaculty of Medicine, Central Clinical School, The University of Sydney, Sydney, New South Wales, Australia.
Richard C KevinLambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia.
Johannes G RamaekersFaculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
Ryan VandreyJohns Hopkins University School of Medicine, Baltimore, MD, USA.
Christopher IrwinSchool of Allied Health Sciences, Griffith University, Gold Coast, Australia.
Paul S HaberFaculty of Medicine, Central Clinical School, The University of Sydney, Sydney, New South Wales, Australia.
Iain S McGregorLambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, New South Wales, Australia. iain.mcgregor@sydney.edu.au.ORCID http://orcid.org/0000-0002-9307-7159
The University of Sydney · AUGriffith University · AUJohns Hopkins University · USMaastricht University · NL

Funding

The Lambert Initiative for Cannabinoid Therapeutics N/A
6 · The paper itself

Abstract

backgroundThe main psychoactive component of cannabis, delta-9-tetrahydrocannabinol (THC), can impair driving performance. Cannabidiol (CBD), a non-intoxicating cannabis component, is thought to mitigate certain adverse effects of THC. It is possible then that cannabis containing equivalent CBD and THC will differentially affect driving and cognition relative to THC-dominant cannabis.

aimsThe present study investigated and compared the effects of THC-dominant and THC/CBD equivalent cannabis on simulated driving and cognitive performance.

methodsIn a randomized, double-blind, within-subjects crossover design, healthy volunteers (n = 14) with a history of light cannabis use attended three outpatient experimental test sessions in which simulated driving and cognitive performance were assessed at two timepoints (20-60 min and 200-240 min) following vaporization of 125 mg THC-dominant (11% THC; < 1% CBD), THC/CBD equivalent (11% THC, 11% CBD), or placebo (< 1% THC/CBD) cannabis. RESULTS/OUTCOMES: Both active cannabis types increased lane weaving during a car-following task but had little effect on other driving performance measures. Active cannabis types impaired performance on the Digit Symbol Substitution Task (DSST), Divided Attention Task (DAT) and Paced Auditory Serial Addition Task (PASAT) with impairment on the latter two tasks worse with THC/CBD equivalent cannabis. Subjective drug effects (e.g., "stoned") and confidence in driving ability did not vary with CBD content. Peak plasma THC concentrations were higher following THC/CBD equivalent cannabis relative to THC-dominant cannabis, suggesting a possible pharmacokinetic interaction. CONCLUSIONS/

interpretationCannabis containing equivalent concentrations of CBD and THC appears no less impairing than THC-dominant cannabis, and in some circumstances, CBD may actually exacerbate THC-induced impairment.

Indexed as

Automobile DrivingAdultCannabidiolCognitionCross-Over StudiesDouble-Blind MethodDronabinolFemaleHallucinogensHumansMaleMarijuana SmokingPsychotropic DrugsVapingYoung AdultCannabidiolDronabinolHallucinogensPsychotropic DrugsCannabidiolCannabisCBDCognitionDrivingTetrahydrocannabinolTHC

Identifiers

PMID31044290
PMCPMC6695367
OpenAlexW2943418795

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.