Luxembourg Study: Cannabis Drug-Driving Cases Up 22% After 2023 Law

Luxembourg's partial legalization has not moved buyers off the illegal market much, and more drivers are testing positive. That is the headline of the first interdisciplinary evaluation of the law that, since July 21, 2023, lets adults grow four plants per household and use cannabis at home.

The paper, in Drug and Alcohol Dependence Reports, was written by the Luxembourg focal point of the EU Drugs Agency at the Health Directorate and the Laboratoire national de santé in Dudelange. It compares police seizures, wastewater and forensic driving cases in the year before and the year after the reform, and adds an online survey.

Why drivers are the warning sign

Levels of the THC metabolite THC-COOH in positive drivers rose 23.7%, which the authors say suggests a subset of users increased their regular consumption after the reform. Luxembourg treats 1 ng/ml of THC in blood as a traffic offense regardless of where the cannabis came from.

In the online survey of 911 users run in June and July 2024, 82.5% said their use had not changed, 38.8% started growing or got cannabis from growers and 56.7% said they were interested in growing in future.

What comes next

The government's 2023–2028 coalition agreement keeps home growing and says it will observe the position of the three neighboring countries, according to the Health Ministry's portal, which gives no update on the earlier pilot for regulated sales. Rules for growers: Luxembourg's home-grow law. Country overview: Luxembourg.