1. Agenzia Regionale di Sanita’ Toscana, Firenze 50141, Italy
2. Epidemiologia, ASL Toscana Centro, Firenze 50135, Italy
3. Department of Mathematical and Statistical Sciences, University of Colorado, Denver, CO 80204, USA
4. Semeion Research Centre of Sciences of Communication, Rome 00128, Italy
5. Institute for the Study of Substance Use and Misuse; Middle Eastern Summer Institute on Drug Use; Founding Editor, Substance Use & Misuse, 9380140, Israel
6. Institute of Clinical Psychology and Psychotherapy and Center of Clinical Epidemiology and Longitudinal Studies (CELOS), Technische Universität Dresden, Dresden 01187, Germany
7. Centre for Interdisciplinary Addiction Research, UKE Hamburg-Eppendorf, Hamburg 20246, Germany
8. Department of Psychiatry, Medical Faculty, University of Leipzig, Leipzig 04103, Germany
9. Centre for Addiction and Mental Health, Toronto, ON M5S 2S1, Canada
10. Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada
11. Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada
12. Department of Psychiatry, University of Toronto, Toronto, ON M5T 1R8, Canada