1. Psychopharmacology, Drug Misuse and Novel Psychoactive Substances Research Unit, Department of Clinical, Pharmaceutical and Biological Sciences, University of Hertfordshire, Hatfield, Hertfordshire, UK
2. Institute of Pharmaceutical Sciences, King’s College London, London, UK
3. National Programme on Substance Abuse Deaths, St George’s, University of London, London, UK
4. Population Health Research Institute, St George’s, University of London, London, UK