Cannabis is Europe’s most-consumed illicit drug. An estimated 13.4 million European adults have used cannabis in the last month. Cannabis also supports a multibillion euro market across the EU, with the share of cannabis resin in many markets losing ground to herbal cannabis. Moreover, treatment demand for cannabis use is rising in many Member States. Such facts underline the importance of having a clear understanding of what is known about cannabis in Europe, for example its impact on public health, how cannabis controls are enforced and the implications of cannabis use for public health responses.

Cannabis is also, perhaps, Europe’s most heavily debated illicit drug. Reviews of the health effects and legal status of cannabis have been carried out by numerous governments and agencies over recent decades. And there is frequent, sometimes heated, discussion about cannabis in the political arena, amongst others in relation to mental health problems, the therapeutic potential of cannabinoids, policing and enforcement, legislation and sentencing.

So it is with great pleasure that I introduce this important body of work on cannabis. It is the most comprehensive publication the EMCDDA has ever produced, and the first time the Centre has attempted to review a single substance in such an all-encompassing way. We must extend our gratitude to all authors who have contributed to this monograph. Excellent work was carried out by Sorad in Sweden, together with reviewers from the EMCDDA’s Scientific Committee, and two independent scientific editors, John Witton and Wendy Swift. The result is a ‘cannabis reader’: a genuine navigational aid to research, debate and policy-making on the substance. The reader approaches cannabis 1from many angles, and will appeal to a wide audience, ranging from ‘beginners’ approaching the subject from other disciplines to drug researchers and professionals who are familiar with the literature and who may appreciate some synthesis of the stateof- the-art in current research or practice.

A cannabis ‘reader’

While cannabis is the most consumed illicit drug worldwide, politically cannabis is a great divider. The illegality of the drug means that the evidence base is often patchy. Lobbyists, libertarians, prohibitionists, think-tanks and commercial interests all by definition speak to the issue from divergent positions. Even research in this area can sometimes appear to be influenced by a political as well as a scientific agenda. The information base in this area is considerable and this fact alone poses a serious challenge to any reader who attempts to navigate it. The goal of this publication is to gather knowledge that will provide a base for improved policy approaches to cannabis in the future. In reaching this goal, leading experts have been asked to clarify what is known and what is not known about cannabis; on which issues scientists agree and which issues are still under debate.

In the development of the monograph the EMCDDA has been keen to provide a nonjudgemental, non-partisan approach to the evidence. However, our aim has also been to enable each author’s ideas to be fully expressed. As leading experts in the field, they are qualified to make judgements where they feel fit, and while most of the monograph is analytical and descriptive, the nature of the subject matter means that, in places, opinions and views are expressed which may be perceived as controversial. Not all the views expressed here are in agreement.

Chapters have been peer-reviewed by the EMCDDA’s Scientific Committee and further edited by qualified scientific editors. The EMCDDA has introduced each chapter, and where opinions are expressed, references to counter-arguments are given, together with a reading list, for those seeking to explore the subject further. Authors have also been given the opportunity to adapt their chapters based on peer feedback. Nonetheless, the chapters remain very much the work of the respective authors. They should be read with the proviso that any views expressed should neither be considered those of the EMCDDA nor the EU institutions in relation to cannabis.

Maximising the shelf-life of the monograph

One of the challenges with working on illicit drugs is that the field is in constant evolution. Use patterns and prevalence, use context and even routes of administration and potency of product can change substantially over time. This is particularly the case for a drug like cannabis, where our understanding of the public health impact of the use of the drug is growing almost daily. Another example of this difficulty is the field of medicinal cannabis, where a number of new medicines are currently being developed in various parts of the world, with considerable uncertainty as to the scope and range of potential therapeutic applications.

What is certain is that this will not be the last monograph published on cannabis. There is a publication cycle of one governmental or think-tank monograph on cannabis every few weeks, and this is likely to continue. Around 20 major books on cannabis are produced by commercial publishers each year, in different languages, with many more in the specialised and scientific literature. So the first volume of the monograph includes an Appendix that sketches a brief history of cannabis monographs and grey literature, referring to the large range of monographs on cannabis. The EMCDDA monograph hopes to (i) identify the producers of literature on cannabis, (ii) illustrate the range in thematic focus of publications and (iii) provide a one-stop research resource for recent major publications on cannabis. This Appendix will reside in a more dynamic form on our website. We hope it will provide an important stepping stone to information on cannabis, published at national, European and global levels.

What this reader adds to the literature

Each chapter is preceded by a section entitled ‘Setting the context’. These are provided to guide readers through the monograph, to offer suggestions for further reading, and to draw attention to the cycles of reporting on cannabis — often annual — by organisations such as the UNODC, the EMCDDA and our Reitox National focal points.

Readers will be interested in knowing what they will gain from this publication. The first is the multidimensional approach to the subject matter. It describes cannabis as seen from different perspectives: historical and cultural, pharmacological, sociological, legal and policy-related, and treatment- and practitioner-related. The second is the monograph’s supranational and European focus. While numerous cannabis monographs have been written at a national or multilateral level in Europe in the past decade, this one can claim EU-wide relevance. It is backed by the EMCDDA’s epidemiological statistics, based on reporting from the Reitox network and the Centre’s privileged position of being able to select a strong team of authors for the monograph. Thirdly, the monograph reflects emerging trends, for example in legislative approaches, treatment demand and provision and cannabis potency.

We hope you will appreciate the effort invested in this monograph. It provides a step back from the EMCDDA’s annual monitoring activities. This wider perspective is both refreshing and eye-opening, even to those of us who are seasoned experts in the field.

Wolfgang Götz
Director, EMCDDA