1. Department of Psychology, University of Fribourg, Fribourg, Switzerland
2. Faculty of Medicine, University of Zurich, Zurich, Switzerland
3. Department of Oral- and Cranio-Maxillo-Facial Surgery, University Hospital Zurich, Zurich, Switzerland
4. Institute of Ethnology, University of Neuchâtel, Neuchâtel, Switzerland
5. Research Coordination, Takiwasi Addiction Treatment Center, Tarapoto, Peru