The International Journal of Neuropsychopharmacology

  • The International Journal of Neuropsychopharmacology / Volume 15 / Issue 07 / August 2012, pp 1003-1014
  • © CINP 2012 The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution-NonCommercial-ShareAlike licence <>. The written permission of Cambridge University Press must be obtained for commercial re-use.
  • DOI: (About DOI), Published online: 05 January 2012


Placebo-related effects in clinical trials in schizophrenia: what is driving this phenomenon and what can be done to minimize it?

Larry Alphsa1 c1, Fabrizio Benedettia2, W. Wolfgang Fleischhackera3 and John M. Kanea4

a1 Janssen Scientific Affairs, LLC, Titusville, NJ, USA

a2 Department of Neuroscience, University of Turin Medical School and National Institute of Neuroscience, Turin, Italy

a3 Department of Psychiatry and Psychotherapy, Medical University of Innsbruck, Innsbruck, Austria

a4 Department of Psychiatry, The Zucker Hillside Hospital, Glen Oaks, NY, USA


The effect of placebo observed in schizophrenia clinical trials represents a growing problem that interferes with signal detection for treatments, increases costs of development, discourages investment in schizophrenia research and delays the introduction of new treatments. This paper seeks to clarify key issues related to this problem and identify potential solutions to them. Differences between placebo effect and response are characterized. Recent insights into the central nervous system mechanisms of placebo effect are described. This is followed by a description of protocol/study design and study conduct issues that are contributing to a growing placebo effect in clinical trials. Potential solutions to these problems are provided.

(Received February 16 2011)

(Reviewed July 22 2011)

(Revised August 19 2011)

(Accepted November 07 2011)

(Online publication January 05 2012)


c1 Address for correspondence: L. Alphs, M.D., Ph.D., Therapeutic Area Leader in Psychiatry, Janssen Scientific Affairs, LLC, 1125 Trenton Harbourton Road, A32501, Titusville, NJ, USA. Tel.: 609-730-3693 Fax: 609-647-0801 Email: