How does cannabidiol (CBD) influence the acute effects of delta-9-tetrahydrocannabinol (THC) in humans? A systematic review.
A. Freeman, Kat Petrilli, Rachel Lees, Chandni Hindocha, Claire Mokrysz, Hv Curran, Rob Saunders, Tom P. Freeman
Neuroscience & Biobehavioral Reviews September 30, 2019 DOI: 10.1016/j.neubiorev.2019.09.036 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Peer reviewed |
|---|---|
| Sample size | 466 |
| Population | Participants in 16 studies of the acute effects of THC |
| Interventions | Cannabidiol (CBD) delta-9-tetrahydrocannabinol (THC) |
| Topics | Cannabis CBD |
| Key findings | Across 16 studies with 466 participants, CBD reduced intense anxiety or psychosis-like effects of THC and blunted some impairments in emotion and reward processing in several studies, but did not consistently influence THC effects across all studies and outcomes. Considerable heterogeneity in dose, route of administration, and THC:CBD ratio meant no clear dose-response profile emerged; the review suggests CBD may interact with some acute effects of THC. |
Abstract
The recent liberalisation of cannabis regulation has increased public and scientific debate about its potential benefits and risks. A key focus has been the extent to which cannabidiol (CBD) might influence the acute effects of delta-9-tetrahydrocannabinol (THC), but this has never been reviewed systematically. In this systematic review of how CBD influences the acute effects of THC we identified 16 studies involving 466 participants. Ten studies were judged at low risk of bias. The findings were mixed, although CBD was found to reduce the effects of THC in several studies. Some studies found that CBD reduced intense experiences of anxiety or psychosis-like effects of THC and blunted some of the impairments on emotion and reward processing. However, CBD did not consistently influence the effects of THC across all studies and outcomes. There was considerable heterogeneity in dose, route of administration and THC:CBD ratio across studies and no clear dose-response profile emerged. Although findings were mixed, this review suggests that CBD may interact with some acute effects of THC.
Comparable studies
Other systematic reviews and meta-analyses on CBD, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Neuroimaging in cannabis use: a systematic review of the literature Cannabis users and controls in neuroimaging studies | 2009 | Systematic review | |
| Cannabis, a cause for anxiety? A critical appraisal of the anxiogenic and anxiolytic properties | 2020 | Systematic review | |
| Effects of Cannabis on Impulsivity: A Systematic Review of Neuroimaging Findings | 2014 | Systematic review | |
| Association between formal thought disorder and cannabis use: a systematic review and meta-analysis Individuals along the psychosis continuum (healthy individuals, patients with... | 2022 | Meta-analysis | n = 5,191 |
| The Relationship Between Cannabis Use and Schizophrenia As a Risk Factor or For Its Therapeutic Potential: A Systematic Review of Evidence | 2025 | Systematic review |
Citations in the library
Cited by 35
- The acute effects of cannabis with and without cannabidiol in adults and adolescents: A randomised, double‐blind, placebo‐controlled, crossover experiment Addiction February 8, 2023
- Cannabis containing equivalent concentrations of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) induces less state anxiety than THC-dominant cannabis Psychopharmacology October 13, 2022
- Acute effects of cannabis on speech illusions and psychotic-like symptoms: two studies testing the moderating effects of cannabidiol and adolescence Psychological Medicine April 28, 2020
- Individual and combined effects of cannabidiol and Δ 9 -tetrahydrocannabinol on striato-cortical connectivity in the human brain Journal of Psychopharmacology May 20, 2022
- Acute effects of different types of cannabis on young adult and adolescent resting-state brain networks Neuropsychopharmacology May 28, 2024
and 30 more in the library
Cites 45
- Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Journal of Psychopharmacology October 5, 2012
- The neuropsychopharmacology of cannabis: A review of human imaging studies Pharmacology & Therapeutics October 20, 2018
- Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Psychopharmacology May 1, 2019
- Acute and chronic effects of cannabinoids on effort-related decision-making and reward learning: an evaluation of the cannabis ‘amotivational’ hypotheses Psychopharmacology September 2, 2016
- Neurophysiological and subjective profile of marijuana with varying concentrations of cannabinoids Behavioural Pharmacology September 1, 2005
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