1. a Novadic-Kentron, Network for Addiction Treatment Services , Vught , The Netherlands
2. d Reinier van Arkel groep, ‘s-Hertogenbosch , The Netherlands
3. b Department of Cognitive Neuroscience , Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre , Nijmegen , The Netherlands
4. c Nijmegen Institute for Scientist-Practitioners in Addiction (NISPA) , Nijmegen , The Netherlands