Trial reportPsychological medicine2017
Acute memory and psychotomimetic effects of cannabis and tobacco both 'joint' and individually: a placebo-controlled trial.
Trial report in Psychological medicine, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 52 papers, 2 of them syntheses 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
52 citing papers in PubMed, 2 syntheses or guidelines pooled it, 99 citations in OpenAlex.
- The Influence of Cannabis and Nicotine Co-use on Neuromaturation: A Systematic Review of Adolescent and Young Adult Studies.Biological psychiatry · 2021Pooled it
- Regular cannabis use is associated with altered activation of central executive and default mode networks even after prolonged abstinence in adolescent users: Results from a complementary meta-analysis.Neuroscience and biobehavioral reviews · 2019Pooled it
- High-Intensity Acute Exercise and Directed Forgetting on Memory Function.Medicina (Kaunas, Lithuania) · 2019Trial
- Experimental Effects of Acute Exercise in Attenuating Memory Interference: Considerations by Biological Sex.Medicina (Kaunas, Lithuania) · 2019Trial
- The Cannabis Research Image Database (CRESIDA): A standardized and validated image set for studying cannabis cue reactivity.Addiction (Abingdon, England) · 2026Article
- Co-Use of Some Substances Associated With Higher Doses in Adolescents: Findings From the Adolescent Brain Cognitive Development Study.The Journal of adolescent health : official publication of the Society for Adolescent Medicine · 2026Article
- Physical Performance Impairment with Cannabis Consumption in Adults Over 12 Hours.Journal of drug education · 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
- Assessment of nicotine and cannabis co-use among adolescents and the association with nicotine and cannabis dependence symptoms.Addictive behaviors · 2025Article
- Using a loose-leaf vaporizer to study tobacco-cannabis co-administration: A proof-of-concept study.Drug and alcohol dependence · 2025Article
- Effects of cannabis smoke and oral Δ9THC on cognition in young adult and aged rats.Psychopharmacology · 2025Article
- The Effects of THC and Nicotine on Attention: A Narrative Review.Current topics in behavioral neurosciences · 2025Review
- Cannabis Use Disorder Symptoms in Weekly Cannabis Users: A Network Comparison Between Daily Cigarette Users and Nondaily Cigarette Users.Cannabis and cannabinoid research · 2024Article
- Investigating sex differences and age of onset in emotion regulation, executive functioning, and cannabis use in adolescents and young adults.Journal of cannabis research · 2024Article
- E-cigarettes may serve as a gateway to conventional cigarettes and other addictive drugs.Advances in drug and alcohol research · 2023Review
- Rates and correlates of cannabis-associated psychotic symptoms in over 230,000 people who use cannabis.Translational psychiatry · 2022Article
- Effects of Prenatal Nicotine, THC, or Co-Exposure on Cognitive Behaviors in Adolescent Male and Female Rats.Nicotine & tobacco research : official journal of the Society for Research on Nicotine and Tobacco · 2022Article
- Preliminary Evidence for Cannabis and Nicotine Urinary Metabolites as Predictors of Verbal Memory Performance and Learning Among Young Adults.Journal of the International Neuropsychological Society : JINS · 2021Article
- Initiation of Moderately Frequent Cannabis use in Adolescence and Young Adulthood is Associated with Declines in Verbal Learning and Memory: A Longitudinal Comparison of Pre- versus Post-Initiation Cognitive Performance.Journal of the International Neuropsychological Society : JINS · 2021Article
- Unraveling the role of cigarette use in neural cannabis cue reactivity in heavy cannabis users.Addiction biology · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundCannabis and tobacco have contrasting cognitive effects. Smoking cannabis with tobacco is prevalent in many countries and although this may well influence cognitive and mental health outcomes, the possibility has rarely been investigated in human experimental psychopharmacological research.
methodThe individual and interactive effects of cannabis and tobacco were evaluated in 24 non-dependent cannabis and tobacco smokers in a randomized, placebo-controlled, double-blind, 2 (cannabis, placebo) × 2 (tobacco, placebo) crossover design. Verbal memory (prose recall), working memory (WM) performance including maintenance, manipulation and attention (N-back), psychotomimetic, subjective and cardiovascular measures were recorded on each of four sessions.
resultsCannabis alone impaired verbal memory. A priori contrasts indicated that tobacco offset the effects of cannabis on delayed recall. However, this was not supported by linear mixed model analysis. Cannabis load-dependently impaired WM. By contrast, tobacco improved WM across all load levels. The acute psychotomimetic effects and ratings of 'stoned' and 'dizzy' induced by cannabis were not altered by tobacco. Cannabis and tobacco had independent effects on increasing heart rate and interacting effects on increasing diastolic blood pressure.
conclusionsRelative to placebo, acute cannabis impaired verbal memory and WM. Tobacco enhanced performance on WM, independently of cannabis. Moreover, we found some preliminary evidence that tobacco may offset the effects of cannabis on delayed, but not immediate, verbal recall. In contrast, the psychotomimetic and subjective effects of cannabis were unaffected by tobacco co-administration. By reducing the cognitive impairment from cannabis, tobacco co-administration may perpetuate use despite adverse health consequences.
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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.