Cannabis, the most widely used illicit substance globally, has prompted various countries to explore regulatory frameworks for its recreational use. The health effects of cannabis regulation, however, remain ambiguous, primarily relying on observational studies. In a pioneering initiative, the “Weed Care” study in Switzerland aims to address this gap by conducting the first randomized controlled trial to evaluate the impact of regulated cannabis access in pharmacies versus the illicit market on problematic cannabis use and overall mental and physical health.
The comprehensive study comprises two phases: a randomized controlled trial spanning 6 months and an ensuing 2-year observational study. A total of 374 participants will be randomly assigned to either the experimental group, gaining legal access to cannabis through pharmacies, or the waiting list control group, representing the existing illicit market scenario in Switzerland. Following the initial 6-month phase, all participants will have legal access to cannabis for the subsequent 2 years, forming the observational study segment. The primary outcome is problematic cannabis use, measured using the Cannabis Use Disorders Identification Test-Revised (CUDIT-R). Secondary outcomes encompass cannabis use patterns, mental health indicators (e.g., depression, anxiety, psychosis), and physical health (e.g., respiratory symptoms). Data collection will occur online every 6 months, with the study receiving approval from the responsible ethics committee and the Swiss Federal Office of Public Health.
The findings of this groundbreaking study are anticipated to furnish a scientific foundation for future deliberations in the realms of addiction medicine and cannabis policy in Switzerland. By adopting a rigorous randomized controlled design, the “Weed Care” study seeks to contribute valuable insights into the potential impact of regulated cannabis access on key health indicators, fostering evidence-based discussions and informed decision-making.