1. 1National Hospital Organization Kurihama Medical and Addiction Center, Yokosuka, Kanagawa, Japan
2. 2Tottori University, Faculty of Medicine, Yonago, Tottori, Japan
3. 3Asahiyama Hospital, Sapporo, Hokkaido, Japan
4. 4University of Lübeck, Lübeck, Germany
5. 5National Centre for Youth Substance Use Research, The University of Queensland, Brisbane, Queensland, Australia