1. Arkin, Department of Research, Amsterdam, the Netherlands
2. Jellinek, TOPGGz department Jacob Obrechtstraat 92, Amsterdam, the Netherlands
3. Amsterdam UMC location University of Amsterdam, Department of Psychiatry, Amsterdam, Meibergdreef 9, the Netherlands
4. Amsterdam Institute for Addiction Research (AIAR), Amsterdam, the Netherlands
5. Department of Psychology, University of Bath, Bath, UK
6. Addictions Research Group, Sangath, Goa, India
7. Department of Prevention, Jellinek, Amsterdam, the Netherlands
8. Velleman Consultancy, Bath, UK