1 Center for Pain Medicine and Mental Health, Saarbrücken D-66111 Saarbrücken, Germany; Department of Psychosomatic Medicine and Psychotherapy, Technische Universität München, Munich, Germany. Electronic address: winfriedhaeuser@googlemail.com.
2 Alan Edwards Pain Management Unit and Division of Rheumatology, McGill University Health Centre, Montreal, QC, Canada.