Components of placebo effect: randomised controlled trial in patients with irritable bowel syndrome

Ted J Kaptchuk. associate professor of medicine 1 , John M Kelley. assistant professor of psychology and statistics 2 , Lisa A Conboy. instructor of medicine 1 , Roger B Davis. associate professor of medicine and biostatistics 3 , Catherine E Kerr. instructor of medicine 1 , Eric E Jacobson. lecturer 4 , Irving Kirsch. professor of psychology 5 , Rosa N Schyner. research associate 1 , Bong Hyun Nam. research fellow 1 , Long T Nguyen. research fellow 1 , Min Park. research coordinator 1 , Andrea L Rivers. research coordinator 1 , Claire McManus. research coordinator 1 , Efi Kokkotou. assistant professor of medicine 3 , Douglas A Drossman. professor of medicine 6 , Peter Goldman. professor emeritus 7 , Anthony J Lembo. assistant professor of medicine 3 1 Osher Research Center, Harvard Medical School, 401 Park Drive, Boston, MA 02215, USA 2 Endicott College, 376 Hale Street, Beverly, MA 01915, USA 3 Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA 4 Department of Social Medicine, Harvard Medical School, 641 Huntington Avenue, Boston, MA 02215, USA 5 Department of Psychology, University of Hull, Hull HU6 7RX 6 Center for Functional GI and Motility Disorders, University of North Carolina School of Medicine, Chapel Hill, NC 27699, USA 7 Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA Correspondence to: T J Kaptchuk ted_kaptchukhms. harvard. edu

Accepted 2 March 2008