Professor Daniele Zullino is Head of the Division of Addiction Psychiatry at the University Hospitals of Geneva. He is a specialist in psychiatry and psychotherapy with additional specialization training in addiction psychiatry. He is the primary investigator of the Geneva Cannabis Pilot Project.

Cannabis remains illegal in most countries, yet its widespread use fuels a thriving black market. To address this, the Swiss Parliament amended the Narcotics Act in 2020, allowing ten-year trials of controlled cannabis distribution. The Geneva project is a key pilot under these revised regulations, providing participants with locally grown cannabis and controlled THC levels. This analysis explores cannabis users' health, motives, and addiction levels using baseline data, employing path analysis to assess direct and indirect relationships.

Methods
Participants, recruited online, access cannabis through a regulated facility ("Cannabinothèque"). Eligible individuals are regular cannabis users from Geneva, aged 18 or older, with no recent addiction treatment. Exclusion criteria include pregnancy, psychotic disorders, or severe health conditions. Baseline data on health and cannabis use motives were collected via the SF-20 Health Survey, Marijuana Motives Measure (MMM), and Cannabis Use Disorder Identification Test – Revised (CUDIT-R). Path analysis, using Maximum Likelihood Estimation (MLE) and Pearson correlation, explored relationships between health, motives, and cannabis use disorder severity.

Results
In the path analysis, SF20-Mental Health was found to significantly predict various motivational mediators, including Coping Motives (p < 0.001) and Enhancement Motives (p = 0.047), which in turn had direct effects on cannabis use severity as measured by the CUDIT-R score. The final model explained 33.6% of the variance in CUDIT-R scores, with higher Coping and Enhancement Motives associated with increased use, while Conformity Motives were negatively associated.

Conclusions
The findings highlight mental health as a key driver of cannabis use severity through its impact on motivational factors. Poor mental health is linked to increased cannabis use for coping and enhancement, both associated with problematic use. Conversely, conformity motives act as a protective factor These results emphasize targeting mental health and specific motives, particularly coping-related use, in interventions to reduce problematic cannabis consumption.