Peter R Wilson, Professor of Anesthesiology and Pain Medicine, Mayo Graduate School of Medicine, Rochester, USAPaul J Watson, Professor of Pain Management and Rehabilitation, Department of Health Sciences, Academic Unit, University of Leicester, Leicester, UKJennifer A Haythornthwaite, Professor, Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, USATroels S Jensen, Professor, Experimental and Clinical Pain Research, Department of Neurology and Danish Pain Research Center, Aarhus University, Denmark