Effects of different methods of cannabis use on cognition and blood THC: A systematic review.
Danial Behzad, S. Patel, R. Besa, Allen W. Chan, Chen Sheng, S. Rueda, Anthony C Ruocco, Patricia Di Ciano
Progress in Neuro-Psychopharmacology and Biological Psychiatry May 1, 2025 DOI: 10.1016/j.pnpbp.2025.111399 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Key findings | Inhaled routes produce higher peak blood THC, while edibles have longer duration; few cognitive differences between methods were found, but some evidence suggests worse attention after vaping and worse memory with high-potency flower plus cannabidiol. |
Abstract
Novel methods of cannabis use are becoming popular, but the differential impact of these new methods on cognition have not been widely studied. Further, the impact of cannabis on cognition is mediated by delta-9-tetrahydrocannabinol (THC), but few studies have directly compared the pharmacokinetics of different methods. This systematic review (PROSPERO, CRD42023442731) was conducted to determine whether the different forms of cannabis and routes of administration have differential acute effects on cognition or blood THC. In total, six studies were found that directly compared the effects of at least two different methods of cannabis administration on cognition and eight studies compared the impact of different methods on blood THC. In general, few differences between methods were found on cognitive performance but two studies found some evidence for worse performance on attention tasks after vaping cannabis versus edibles or smoked cannabis. One study found worse performance on a memory task in participants who smoked high potency flower with cannabidiol compared to a group of concentrates users. Despite this, the clear consensus is that inhaled routes of administration result in higher peak levels of THC, while edible cannabis has a longer duration of action. Additionally, one study found an inverse correlation between blood THC and cognition. Given that THC levels are used to detect impairment, this suggests that the ability to detect impairment may vary by method, with edibles presenting more of a challenge. More studies are needed to understand the effects of these newer methods of cannabis administration on performance and blood THC.
Comparable studies
Other systematic reviews and meta-analyses on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Effects of cannabis use on outcomes of psychotic disorders: systematic review People with psychotic disorders, as examined in 13 longitudinal studies | 2008 | Systematic review | |
| The Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample Patients with established schizophrenia (meta-analysis: 572) and patients with... | 2010 | Meta-analysis and cross-sectional observational study | n = 700 |
| Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review | 2020 | Systematic review | |
| Neuroimaging in cannabis use: a systematic review of the literature Cannabis users and controls in neuroimaging studies | 2009 | Systematic review | |
| Human Laboratory Studies on Cannabinoids and Psychosis. Healthy human subjects and individuals with schizophrenia | 2016 | Systematic review |
Citations in the library
Cited by 2
Cites 16
- Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Journal of Psychopharmacology October 5, 2012
- Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Psychopharmacology May 1, 2019
- The effect of cannabis edibles on driving and blood THC. Journal of Cannabis Research May 31, 2024
- Acute and chronic cannabis vapor exposure produces immediate and delayed impacts on phases of fear learning in a sex specific manner. Psychopharmacology February 1, 2026
- Combined effect of alcohol and cannabis on simulated driving. Psychopharmacology May 2022
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