Updating the definition of pain

aResearch Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom bDepartment of Psychology, University of British Columbia, Vancouver, BC, Canada *Corresponding author. Address: Research Department of Clinical, Educational and Health Psychology, University College London, Gower St, London WC1E 6BT, United Kingdom. Tel.: 00442076791608; fax: 00442079161989. E-mail address: [email protected] (A. C.d.C. Williams). Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.