Research Article Following (the Roots) of Kratom (Mitragyna speciosa): The Evolution of an Enhancer from a Traditional Use to Increase Work and Productivity in Southeast Asia to a Recreational Psychoactive Drug in Western Countries Eduardo Cinosi, 1,2 Giovanni Martinotti, 1,2 Pierluigi Simonato, 1 Darshan Singh, 3 Zsolt Demetrovics, 4 Andres Roman-Urrestarazu, 5,6 Francesco Saverio Bersani, 1,7 Balasingam Vicknasingam, 3 Giulia Piazzon, 1 Jih-Heng Li, 8 Wen-Jing Yu, 8 Máté Kapitány-Fövény, 4,9,10 Judit Farkas, 4,10 Massimo Di Giannantonio, 2 and Ornella Corazza 1,7 1 Centre for Clinical & Health Research Services, School of Life and Medical Sciences, University of Hertfordshire, College Lane Campus, Hatfeld, Herts AL10 9AB, UK 2 Department of Neuroscience, Imaging and Clinical Sciences, Gabriele D’Annunzio University, Chieti, Italy 3 Centre for Drug Research, Universiti Sains, Penang, Malaysia 4 Institute of Psychology, E¨ otv¨ os Lor´ and University, Budapest, Hungary 5 London School of Economics and Political Science, LSE Health and Social Care, London, UK 6 Department of Psychiatry, University of Cambridge, Cambridge, UK 7 Department of Neurology and Psychiatry, Sapienza University of Rome, Rome, Italy 8 School of Pharmacy and Ph.D. Program in Toxicology, Kaohsiung Medical University, Kaohsiung, Taiwan 9 Faculty of Health Sciences, Semmelweis University, Budapest, Hungary 10 Ny´ ır˝ o Gyula Hospital, National Institute of Psychiatry and Addictions, Budapest, Hungary Correspondence should be addressed to Ornella Corazza; o.corazza@herts.ac.uk Received 7 August 2015; Revised 13 October 2015; Accepted 15 October 2015 Academic Editor: Yu-Ping Tang Copyright © 2015 Eduardo Cinosi et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te use of substances to enhance human abilities is a constant and cross-cultural feature in the evolution of humanity. Although much has changed over time, the availability on the Internet, ofen supported by misleading marketing strategies, has made their use even more likely and risky. Tis paper will explore the case of Mitragyna speciosa Korth. (kratom), a tropical tree used traditionally to combat fatigue and improve work productivity among farm populations in Southeast Asia, which has recently become popular as novel psychoactive substance in Western countries. Specifcally, it (i) reviews the state of the art on kratom pharmacology and identifcation; (ii) provides a comprehensive overview of kratom use cross-culturally; (iii) explores the subjective experiences of users; (iv) identifes potential risks and side-efects related to its consumption. Finally, it concludes that the use of kratom is not negligible, especially for self-medication, and more clinical, pharmacological, and socioanthropological studies as well as a better international collaboration are needed to tackle this marginally explored phenomenon. 1. Introduction Kratom (Mitragyna speciosa Korth., of the Rubiaceae family) is a 4–16-metre high tropical tree, indigenous to Southeast Asia, the Philippines, and New Guinea. Traditionally, in certain regions of Southeast Asia, the chopped fresh or dried leaves of the tree are chewed or made into tea by local manual labourers to combat fatigue and improve work productivity [1]. In addition, kratom preparations have also been used for centuries during socioreligious ceremonies and to treat