A study investigating the acute dose-response effects of 13 mg and 17 mg Delta 9- tetrahydrocannabinol on cognitive-motor skills, subjective and autonomic measures in regular users of marijuana.
A Weinstein, O Brickner, H Lerman, M Greemland, M Bloch, H Lester, R Chisin, Y Sarne, Raphael Mechoulam, Rachel Bar-Hamburger, N Freedman, E Even-Sapir
Journal of Psychopharmacology June 2008 DOI: 10.1177/0269881108088194 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized crossover trial Peer reviewed |
|---|---|
| Sample size | 14 |
| Population | Regular users of marijuana |
| Intervention | Delta 9-tetrahydrocannabinol (THC) |
| Dose | 13 mg and 17 mg |
| Duration | Two test days |
| Measures | virtual reality maze task, Wisconsin Card Sorting Test (WCST), gambling task, subjective ratings |
| Topics | Cannabis |
| Key findings | In regular marijuana users, smoking 17 mg THC impaired performance on a virtual maze task, the Wisconsin Card Sorting Test, and a gambling task, while 13 mg THC affected only the card-sorting test; both doses increased subjective ratings of drug effect and high. |
Abstract
Heavy use of marijuana is claimed to damage critical skills related to short-term memory, visual scanning and attention. Motor skills and driving safety may be compromised by the acute effects of marijuana. The aim of this study was to investigate the acute effects of 13 mg and 17 mg Delta 9-tetrahydrocannabinol (THC) on skills important for coordinated movement and driving and on subjective and autonomic measures in regular users of marijuana. Fourteen regular users of marijuana were enrolled. Each subject was tested on two separate days. On each test day, subjects smoked two low-nicotine cigarettes, one with and the other without THC. Seventeen mg THC was included in the cigarette on one test day and 13 mg on the other day. The sequence of cigarette types was unknown to the subject. During smoking, heart rate and blood pressure were monitored, and the subjects performed a virtual reality maze task requiring attention and motor coordination, followed by 3 other cognitive tasks (Wisconsin Card Sorting Test (WCST), a "gambling" task and estimation of time and distance from an approaching car). After smoking a cigarette with 17 mg THC, regular marijuana users hit the walls more often on the virtual maze task than after smoking cigarettes without THC; this effect was not seen in patients after they smoked cigarettes with 13 mg THC. Performance in the WCST was affected with 17 mg THC and to a lesser extent with the use of 13 mg THC. Decision making in the gambling task was affected after smoking cigarettes with 17 mg THC, but not with 13 m THC. Smoking cigarettes with 13 and 17 mg THC increased subjective ratings of pleasure and satisfaction, drug "effect" and drug "high". These findings imply that smoking of 17 mg THC results in impairment of cognitive-motor skills that could be important for coordinated movement and driving, whereas the lower dose of 13 mg THC appears to cause less impairment of such skills in regular users of marijuana.
Comparable studies
Other randomized controlled trials on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Cannabidiol inhibits THC-elicited paranoid symptoms and hippocampal-dependent memory impairment Healthy participants | 2012 | Randomized controlled trial | n = 48 |
| Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing Healthy, English-native, right-handed men who had used cannabis 15 times or less in... | 2009 | Double-blind, randomized, placebo-controlled crossover trial | n = 15 |
| Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Healthy male subjects | 2012 | Randomized controlled trial | n = 16 |
| Modulation of Mediotemporal and Ventrostriatal Function in Humans by Δ9-Tetrahydrocannabinol Healthy, native English-speaking, right-handed men of white race/ethnicity who had used... | 2009 | Randomized controlled trial | n = 15 |
| Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition Healthy volunteers with a history of light cannabis use | 2019 | Randomized, double-blind, within-subjects crossover | n = 14 |
Citations in the library
Cited by 17
- Smoked Cannabis' Psychomotor and Neurocognitive Effects in Occasional and Frequent Smokers Journal of Analytical Toxicology March 4, 2015
- Effects of Cannabis on Impulsivity: A Systematic Review of Neuroimaging Findings Current Pharmaceutical Design May 10, 2014
- Cognitive Effects of Cannabis Use: A Comprehensive Review Across Domains Neurology International July 1, 2025
- Acute effects of Δ9-tetrahydrocannabinol on computational measures of neurocognitive processes are related to recent cannabis use among adolescents and young adults. Frontiers in adolescent medicine 2025
- Nabilone Impairs Spatial and Verbal Working Memory in Healthy Volunteers. Cannabis and Cannabinoid Research February 1, 2024
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