Who is driving under the influence of cannabis in Germany? Findings of a large-scale online survey

Background: Germany is planning to reform its legal approach to cannabis, allowing possession and cultivation of cannabis for recreational purposes. Against this backdrop, driving under the influence of cannabis (DUIC) is likely to become an increasingly relevant policy issue.

Methods: To assess the effect of this policy reform on a) the prevalence of cannabis use and b) DUIC, repeated cross-sectional surveys will be conducted at three measurement points (2023-2025) in a quasi-experimental research approach in Germany and Austria (comparison group). This presentation will focus on the baseline data collected in December 2023 from N = 8,924 individuals in Germany aged between 18 and 64 years. In addition to analysing the 12-month prevalence of cannabis use and self-reported DUIC, an exploratory latent class analysis (LCA) will be used to identify distinct subpopulations of at least monthly cannabis users who are prone to DUIC. The latent class indicators for DUIC profile types will include self-reported DUIC, cannabis use behaviour, use of other substances, personality traits, education on cannabis, risky driving behaviour, as well as risk perception of driving under the influence. Demographic grouping variables, such as sex, age, and education, will also be included to test for measurement invariances and examine differences in the prevalence of DUIC profile types.

Results / Conclusion: The baseline data collection has just been completed, and data analysis is currently underway. We anticipate that these results can provide an evidence-based foundation for developing prevention measures that target specific risk groups.

This report is based on parts of the research project carried out at the request of the Federal Ministry of Transport and Digital Infrastructure, represented by the Federal Highway Research Institute, under research project No. FE 82.0816/2023. The authors are solely responsible for the content.