Pilot-Study for the Comparison of Biomarkers Between Regular Cannabis Users and Non-Users

The relevance of driving under the influence of cannabis is becoming increasingly important in the context of legalization. However, the measurement of tetrahydrocannabinol (THC) blood concentration is an inadequate marker for assessing driving impairment. Currently, there is no reliable marker available for estimating the time of last cannabis inhalation, which would provide a promising tool for regulating driving under the influence of cannabis. This pilot study aims to explore potential biomarkers and factors that could approximate the timing of the last cannabis inhalation, with emphasis on the potential explanation of interindividual differences in THC pharmacokinetics and -dynamics. The results will assist future research aimed at improving the ability to distinguish between impaired and unimpaired cannabis users in road traffic. These findings are of significant importance for road safety and for society at large, as they may provide more objective markers for cannabis inhalation, thereby permitting a methodologically sound evaluation of driving under the influence of cannabis.

NCT Number	NCT06975020
Lead Sponsor	University of Basel Collaborators: University Psychiatric Clinics Basel, Department of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Basel, Switzerland, Biopharmacy, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland, Institute of Forensic Medicine, University of Basel, Basel, Switzerland
Conditions	Driving Under the Influence of Cannabis
Enrollment	120 participants
Start Date	2025-12-19
Primary Completion	2026-12-31 (estimated)
Study Completion	2027-01-01 (estimated)
Updated on ClinicalTrials.gov	2025-12-26