The influence of cannabis on real time higher-order driving skills: a scoping review

Cannabis use is frequently detected in motor vehicle crashes. While research has found an increased crash risk of driving under the influence of cannabis, research on the effects of cannabis, or THC, on driving behaviour seems to be somewhat limited to vehicle control. Our objectives were to map available research into the effects of THC on higher-order driving skills during actual driving. A scoping review was conducted by systematically searching Scopus, PubMed and TRID between 2003 and 2024. After applying inclusion criteria to 2326 studies, 40 studies underwent full-text review, after which three studies met the inclusion criteria. These studies examined higher-order driving skills using driving simulators or real-world driving and measured executive function, attention, time perception, decision making, visual search and vigilance. The results of this study revealed a scarcity of research investigating the effects of THC on higher-order driving skills. While the results of the included studies show no or only small effects of THC on higher-order driving skills, there is so little research available that no conclusions can be made. There seems to be limited evidence addressing the impact of THC on critical higher-order cognitive abilities which are essential for safe driving. This highlights a significant gap in the body of research underlining the need for future research to explore these skills in a driving environment. Research using simulators combined with eye-tracking might provide these important insights.