Mark W. Green is Professor of Neurology, Anesthesiology and Rehabilitation Medicine, and Director of Headache and Pain Medicine, Mount Sinai School of Medicine, New York, USA.
Philip R. Muskin is Professor of Clinical Psychiatry at Columbia University College of Physicians and Surgeons, Chief of Consultation-Liaison Psychiatry at the Columbia University Medical Center of the New York Presbyterian Hospital, and a faculty member of the Columbia University Psychoanalytic Center for Research and Training, New York, USA.