1. IrisZorg Institute for Addiction Care and Sheltered Housing Arnhem The Netherlands
2. Nijmegen Institute for Scientist‐Practitioners in Addiction (NISPA) Radboud University Nijmegen Nijmegen The Netherlands
3. Behavioural Science Institute Radboud University Nijmegen Nijmegen The Netherlands
4. Hornsveld Psychologen Praktijk Utrecht The Netherlands
5. Novadic-Kentron Center for Addiction Treatment Vught The Netherlands