Study on Cannabis Regulation

Dianova gathers several experts to carry out a study on the consequences of the regulation of cannabis

Study on cannabis

This study has been conducted to investigate the validity of the discussions on the legalization or regulation of cannabis; analyse their scientific, legal and political grounds and what would be their main consequences for the population at large as well as for specific groups – photo: Shutterstock, CC

By Antonio Jesús Molina Fernández – Within organizations working in fields related to addictive behaviour, the debate over the regulation of cannabis and its consequences remain ongoing. The main problem with this debate is that it continues to be based on attitudes manifestly “for/against”, that are typically biased or that claim to confirm initial stances, without carrying out any reflection and analysis processes. Actually, as it frequently happens, said stances are rather based on the wealth of myths and legends that accompany the history of cannabis use than on evidence and proven facts that may result from research, analysis and reflection.

Dianova has chosen a different way, entrusting a task force with the mandate to carry out a study based not on the participants’ own opinions, but an in-depth analysis of the international reality, its limitations and possibilities.

The study was carried out with the participation of a number of international experts on the subject, coming from different fields in connection to the regulation of cannabis (policy makers, prevention and intervention, research, civil society, etc.) whose stances on this issue were sometimes dramatically different, including the extremes of this debate and the intermediary points of consensus.

The study was carried out in several stages:

  • Between January and March 2019 a search of the literature was carried out and the main research studies published over the last ten years were systematic reviewed and the main aspects of this debate identified.
  • Between April and October 2019, international experts were interviewed. This group consisted of 18 people with extensive experience on this issue and was covering many of the aspects related to cannabis regulation: prevention, intervention, social activism or policy-making. The interviews were carried out in 3 different languages (Spanish, English and Italian).
  • Between October and November the interviews were analyzed during thematic sections.
  • Between December and January, discussion groups and expert panels were implemented with the aim of developing and validating the conclusions drawn from the interviews.

In a last step, the complete report as well as an executive summary were written including all processes and results of the study. This report has been the subject of various discussions and contributions that will be finalized at Dianova International’s General Assembly in November. A decision will also be made to validate the modifications to the Dianova Network’s Manifesto in the area of addiction and more specifically with respect to the regulation of the different uses of cannabis.

As the person in charge of this study, I should mention that we did not try to set out any dogmatic views about cannabis regulation, but endeavoured rather to explain all the existing stances, techniques and hypotheses so as to be able to draw valid conclusions based on information and data. A simple method has been implemented to analyse the different aspects of cannabis regulation at the international level, while at the same time studying in depth the causes and consequences of this problem. It has been a quite stimulating and rewarding project, both for myself and my team (composed of Paula Medrano, Pol Comellas and myself). I hope you’ll find this study worthwhile reading and that it will shed some light on this current, yet contentious issue.


Many thanks to Dianova International, for their incentive and for giving us support and freedom of action in this research study. It has been exemplary in each and every respect. Many thanks also all those who participated in this study, including the Faculty of Psychology of the Complutense University of Madrid, especially the Social, Work and Differential Psychology Department.

Download study (pdf)

Study on the Regulation and Legalization of the Therapeutic and Recreational Uses of Cannabis and their Addiction, Social and Health-Related Risks


Rolles S, Murkin G. How to Regulate Cánnabis: A Practical Guide. London: Transform Drug Policy Foundation; 2016.

Hall W, Lynskey M. The challenges in developing a rational cannabis policy. Curr Opin Psychiatry. 2009; 22:258–262.

Baptista-Leite R. The road towards the responsible and safe legalization of cannabis use in Portugal. Acta Med Port. 2018; 31:115-125.

Hall W, Lynskey M. Evaluating the public health impacts of legalizing recreational cannabis use in the United States. Addiction. 2015; 111: 1764–1773. (4)

Isorna Folgar M, Rial Baubeta A, Pascual Mollá M. El consumo de cannabis desde la evidencia científica: el peligro de banalizar el consumo y riesgos de una posible legalización o regulación. Salud Drogas. 2020; 20: 1-4.

Creswell, J W. Research Design: Qualitative, Quantitative and Mixed Methods Approaches. 4th ed. Thousand Oaks: Sage; 2014. (6)

Casas M, Bruguera E, Roncero C, San L. Consenso de la Sociedad Española de Psiquiatría sobre el consumo de cannabis. Barcelona: FEPSM; 2007.

Hall W, Lynskey M. The challenges in developing a rational cannabis policy. Curr Opin Psychiatry. 2009; 22:258–262.

Cannabis: Issues for policy makers. Brussels: EURAD; 2012.

Hall W. What has research over the past two decades revealed about the adverse health effects of recreational cannabis use? Addiction. 2014; 110:19–35.

Stockings E, Hall W, Lynskey M, Morley K, Reavley N, Strang J et al. Prevention, early intervention, harm reduction, and treatment of substance use in young people. Lancet Psychiatry. 2016; 3: 280–96.

Vázquez N, Muñoz L, Juárez O, Ariza C. ¿Qué funciona en la prevención selectiva del consumo de alcohol y cánnabis en jóvenes vulnerables? Rev Esp Salud Pública. 2018; 92:1-18.

WHO. The health and social effects of nonmedical cannabis use. Geneva: WHO; 2016.