Driving under the influence of cannabis: A 5-year retrospective Italian study.

Introduction: Cannabis consumption is associated with driving impairment and increased crash risk, endangering road safety. Toxicological analyses play a fundamental role in detecting a recent consumption of psychoactive substances. The aim of this study was to examine the concentration of cannabinoids in blood samples of driving-under-the-influence (DUI) offenders in order to investigate whether delayed sample collection affects the toxicological assessment of the offenders.