1. Department of Psychology, University of Fribourg, Fribourg, Switzerland
2. Faculty of Medicine, Institute of Anatomy, 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. Department of Psychology, University of California, Berkeley, Berkeley, California
6. Takiwasi Center for the Rehabilitation of Drug Addictions and Research in Traditional Medicine, Tarapoto, Peru
7. Centre for Addiction and Mental Health, Toronto, Ontario, Canada