Trial reportPsychopharmacology2022
Combined effect of alcohol and cannabis on simulated driving.
Trial report in Psychopharmacology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers, 1 of them a synthesis that pooled 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.
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
24 citing papers in PubMed, 1 synthesis or guideline pooled it, 42 citations in OpenAlex.
- Association of driving with blood delta-9-tetrahydrocannabinol: a systematic review.The international journal of neuropsychopharmacology · 2025Pooled it
- Dose-Dependent Effects of Cannabis Edibles on Simulated Driving Performance: A Randomized Clinical Trial.JAMA network open · 2026Trial
- Impact of Cannabis Edibles Combined With Alcohol on Driving, Field Sobriety Performance, and Subjective Effects: A Within-Participant Crossover Trial.JAMA network open · 2026Trial
- Potency-related effects of smoked cannabis on simulated driving performance: a randomized, controlled crossover trial.Scientific reports · 2026Trial
- Interpol review of forensic toxicology, 2023-2025.Forensic science international. Synergy · 2026Review
- Retrospective Event-Level Patterns of Cannabis-Impaired Driving.Journal of studies on alcohol and drugs · 2026Article
- The use of THC cutoff levels in blood and oral fluid for detecting impairment in frequent cannabis users who smoked cannabis the "evening before".Psychopharmacology · 2026Article
- Cognitive performance and subjective effects the morning after last use of smoked cannabis by adults who use cannabis frequently: An observational study.Drug and alcohol dependence reports · 2026Article
- Driving by frequent cannabis users 'the morning after' last use of smoked cannabis: an observational driving simulator study.Journal of cannabis research · 2026Article
- Effects of naturalistic doses of cannabis edibles on cognition and association with blood THC.Psychopharmacology · 2026Observational
- Edible cannabis use on simulated driving performance.Traffic injury prevention · 2026Article
- Recent Advances in the Science of Cannabis-Impaired Driving.Current addiction reports · 2026Review
- Cannabis in road traffic - a retrospective analysis to identify possible cut-off-values.Forensic science, medicine, and pathology · 2025Article
- The association between cannabis and alcohol co-use and momentary subjective effects: Risks for increasingly hazardous cannabis use.Drug and alcohol dependence · 2025Article
- Event-level influences of alcohol, cannabis, and simultaneous use on perceived driving risk.Experimental and clinical psychopharmacology · 2025Article
- The driving-related attitudes, beliefs and behaviours of cannabis users in the Australian Capital Territory following decriminalisation.Drug and alcohol review · 2025Article
- Proximal antecedents and acute outcomes of simultaneous alcohol and cannabis use: Systematic review of daily- and event-level studies.Alcohol, clinical & experimental research · 2025Review
- The effects of simultaneous alcohol and cannabis use on subjective drug effects: A narrative review across methodologies.Alcohol, clinical & experimental research · 2024Review
- The effect of cannabis edibles on driving and blood THC.Journal of cannabis research · 2024Article
- Cannabis and Driving in Older Adults.JAMA network open · 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
18 authors at 6 institutions in 6 countries.
Funding
Abstract
rationaleWith alcohol and cannabis remaining the most commonly detected drugs in seriously and fatally injured drivers, there is a need to understand their combined effects on driving.
objectivesThe present study examined the effects of combinations of smoked cannabis (12.5% THC) and alcohol (target BrAC 0.08%) on simulated driving performance, subjective drug effects, cardiovascular measures, and self-reported perception of driving ability.
methodsIn this within-subjects, double-blind, double-dummy, placebo-controlled, randomized clinical trial, cannabis users (1-7 days/week) aged 19-29 years attended four drug administration sessions in which simulated driving, subjective effects, cardiovascular measures, and whole blood THC and metabolite concentrations were assessed following placebo alcohol and placebo cannabis (<0.1% THC), alcohol and placebo cannabis, placebo alcohol and active cannabis, and alcohol and active cannabis.
resultsStandard deviation of lateral position in the combined condition was significantly different from the placebo condition (p < 0.001). Standard deviation of lateral position was also significantly different from alcohol and cannabis alone conditions in the single task overall drive (p = 0.029 and p = 0.032, respectively), from the alcohol alone condition in the dual task overall drive (p = 0.022) and the cannabis alone condition in the dual task straightaway drive (p = 0.002). Compared to the placebo condition, the combined and alcohol conditions significantly increased reaction time. Subjective effects in the combined condition were significantly greater than with either of the drugs alone at some time points, particularly later in the session. A driving ability questionnaire showed that participants seemed unaware of their level of impairment.
conclusionCombinations of alcohol and cannabis increased weaving and reaction time, and tended to produce greater subjective effects compared to placebo and the single drug conditions suggesting a potential additive effect. The fact that participants were unaware of this increased effect has important implications for driving safety.
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.