1. Faculty of Medicine, National Heart and Lung Institute, Imperial College London, London, UK
2. Drug Science, London, UK
3. Institute of Epidemiology and Health Care, University College London, London, UK
4. Global Drug Survey, London, UK
5. Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
6. Consultant Anaesthetist and Pain Specialist, University College London, London, UK
7. School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK
8. Independent homeless and drug consultant, UK
9. Department of Psychiatry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
10. Department of Management, London School of Economics & Political Science, London, UK
11. Independent Consultant in Veterinary Anaesthesia, UK
12. Clinical Department, Humankind Charity, Durham, UK
13. Transform Drug Policy Foundation, UK