In this preprint (2022), eighteen experts reformulated the Dutch MDMA policy using multi-decision multi-criterion decision analysis (MD-MCDA) with a science-based approach. The optimal policy model was defined by a set of 22 policy instrument options. Implementation of the optimal policy model, includes regulated MDMA sales, decreases health harms, MDMA-related organised crime, and environmental damage, as well as, increases state revenues, and quality of MDMA products and user information.

Abstract

“Background: MDMA(ecstasy, 3,4-methylenedioxymethamphetamine)has a relatively low harm and low dependence liability but is scheduled on List I of the Dutch Opium Act together (“hard drugs”). Concerns surrounding increasing MDMA-related criminality coupled with the possibly inappropriate scheduling of MDMA initiated a debate to revise the current Dutch ecstasy policy.

Methods: An interdisciplinary group of eighteen experts on health, social harms, and drug criminality and law enforcement reformulated science-based the Dutch MDMA policy using multi-decision multi-criterion decision analysis (MD-MCDA). The experts collectively formulated policy instruments and rated their effects on 25 outcome criteria, including health, criminality, law enforcement and financial issues, thematically grouped in six clusters.

Results: The experts scored the effect of 22 policy instruments, each with 2-7 different mutually exclusive options, on 25 outcome criteria. The optimal policy model was defined by the set of 22 policy instrument options which gave the highest overall score on the 25 outcome criteria. Implementation of the optimal policy model, including regulated MDMA sales, decreases health harms, MDMA-related organised crime, and environmental damage, as well as, increases state revenues, and quality of MDMA products and user information. This model was slightly modified to increase its political feasibility. Sensitivity analyses showed that the outcomes of the current MD-MCDA are robust and independent of variability in weight values.

Conclusion: Present results provide a feasible and realistic set of policy instrument options to revise the legislation toward a rational MDMA policy that is likely to reduce both adverse (public) health risks and MDMA-related criminal burden.”

Authors: Jan van Amsterdam, Gjalt-Jorn Y. Peters, Joost Breeksema, Ed Pennings, Tom Bickman, Kaj Hollemans, Johannes G. Ramaekers, Cees Maris, Floor van Bakkum, Ton Nabben, Willem Scholten, Tjibbe Reitsma, Judith Noijen, Raoul Koning & Wim van den Brink

Summary

MDMA (ecstasy) is scheduled on List I of the Dutch Opium Act together with hard drugs, which may be inappropriate.

Eighteen experts formulated policy instruments for the Dutch MDMA policy using MD-MCDA, and rated their effects on 25 outcome criteria.

Results: The optimal policy model for MDMA sales was defined by the set of 22 policy instrument options that gave the highest overall score on 25 outcome criteria. This policy model was slightly modified to increase its political feasibility.

A group of experts used the multi-decision multicriteria decision analysis (MD-MCDA) approach to rank 95 policy instrument options and identify the optimal MDMA policy model that considers both adverse (public) health risks and MDMA-related criminal burden.

18 experts were invited to participate in the expert panel. They had expertise in several domains and were independent of political parties or ministries involved in drug policy or drug enforcement. The experts defined 25 outcome criteria for drug policies, grouped in 6 clusters: use, health, crime, finances, international, environment. They formulated 22 policy instruments, each having 2-7 options, thus resulting in 95 policy instrument options. The MD-MCDA process defined five drug policy models, including the “coffeeshop model”, the “adapted coffeeshop model”, the “free market model”, and the “repressive model”. The optimal model achieved the highest overall weighted score on the policy outcomes.

After scoring all policy options and weight factors, an optimal policy model was automatically generated. A so-called “X-shop model” was then constructed by selecting the applicable set of instrument options which legally impose regulated distribution and sales of ecstasy. Experts rated the effects of policy instrument options on 25 policy outcomes related to ecstasy based on their own expertise and the expert information provided by an extensive ‘state-of-the-art’ document. Before scoring the 95 policy instrument options, consensus anchor values were set by the experts for each of the 25 outcomes. These anchors were adjusted to reflect the current legal situation for 12 of the 25 outcomes.

Experts rated policy instrument options in two parallel groups over three days, and rated all sets of policy instrument options successively per cluster. If consensus wasn’t attained, the average of the individual scores was set as the final score. In step 5 and 6, weights were assigned to each outcome criterion within the outcome cluster and the six outcome clusters, and a mean value was calculated for each weight value. The weight of the outcome cluster with the highest mean value was set at 100.

We rescaled the mean W2-values of the 25 outcome criterion clusters, multiplied the results by the rescaled W1 of the corresponding cluster, and summed the results to get the overall score.

Results

MDMA is prohibited in the Netherlands. The Dutch Opium law does not cover the issues of packaging, age limit, price, quality requirements and management.

The experts rated 95 policy instrument options on 22 outcomes and attributed weight values to each of the 25 outcomes and the 6 outcome clusters. The optimal policy model scored 13,270 points higher/better than the current situation and the worst possible model scored 7,252 points lower/worse.

Options like ‘possession prohibited’, ‘high priority for fighting serious crime’, ‘no subsidy for health education’, ‘abstinence as prevention perspective’ and ‘no monitoring’ had a strong negative impact on the overall score.

In order to position the optimal model, two legal drug models in the Netherlands were compared. The optimal model scored better than the adapted coffeeshop model and the coffeeshop model. To accommodate political feasibility and social acceptance of regulated ecstasy sales, the optimal model was slightly adjusted at six minor points to construct a new, nearly optimal and a politically more feasible model: the X-shop model. The X-shop model is superior to the optimal model at all cluster levels.

We conducted two types of sensitivity analyses to assess the robustness of the findings to changes in the scores and the weights that were employed. The results revealed two clusters: a high-scoring (better outcome) cluster and a low-scoring (worse outcome) cluster. The six models were robust against changes in weight factors, and the same stable clustering was obtained when the weighting factors of each expert were applied.

Discussion

The current MD-MCDA based on experts ratings of 95 policy options on 25 policy outcomes has led to an optimal model for regulating MDMA sales.

The X-shop model was modified to be more politically feasible and to reduce the level of MDMA-related organized crime. It also provides better protection of vulnerable users, though incrimination of users will slightly increase due to stricter regulation. According to the proposed X-shop model, ecstasy use will slightly increase, but the prevalence of ecstasy dependence will not increase because of the low dependence potential of ecstasy. Regulated ecstasy sales in the X-shop model generate modest state revenues, but result in lower expenses for drug enforcement. The optimal model includes the ‘inter se’ option for treaty modification, which allows a group of like-minded states to reach agreements among themselves.

The Netherlands has implemented legislation against the production and trade of MDMA. This legislation has a positive impact on the fight against organised crime, and the Netherlands is working with other countries to implement similar legislation.

The main strength of this study is that the expert panel consisted of experts from a broad range of expertise domains. Moreover, the rating of the policy options was performed in an efficient manner using a structured decision-making model.

The impact of subjectivism has been mitigated by including experts from law enforcement agencies and experts with a relatively conservative attitude towards the liberalization of drug laws. Furthermore, the selection of policy instruments and outcomes was not idiosyncratic.

Using multi-decision multi-criterion decision analysis (MD-MCDA), the optimal MDMA policy model was found, which predicts a major health benefit and takes into account the current criminal burden.

These results would not have been achieved without the experts who carried out their work with great dedication, expertise, and enthusiasm.