title: High heterogeneity and low reliability in the diagnosis of major depression will impair the development of new drugs.
abstract: CONCLUSIONS
  Major depressive disorder is a common diagnosis associated with a high burden of disease that has proven to be highly heterogeneous and unreliable. Treatments currently available demonstrate limited efficacy and effectiveness. New drug development is urgently required but is likely to be hindered by diagnostic limitations.
  
  
  BACKGROUND
  D.J.C. has received grants and personal fees from Eli Lilly, Janssen-Cilag, Roche, Allergen, Bristol-Myers Squibb, Pfizer, Lundbeck, AstraZeneca, Hospira, Organon, Sanofi-Aventis, and Wyeth during the writing of this review. C.P. has received grant support from Janssen-Cilag, Eli Lilly, Hospira (Mayne), AstraZeneca, and received honoraria for consultancy to Janssen-Cilag, Eli Lilly, Hospira (Mayne), AstraZeneca, Pfizer, Schering Plough, and Lundbeck. Over the past 2 years he has participated on advisory boards for Janssen-Cilag and Lundbeck, and received honoraria for talks presented at educational meetings organised by AstraZeneca, Janssen-Cilag and Lundbeck. M.H. has received personal fees or grants from Lundbeck, AstraZeneca and Servier during the writing of this review. A.H.Y. reports personal fees from Lundbeck, Sunovion, AstraZeneca and Janssen outside the submitted work. I.P.E. has received personal fees or grants from Lundbeck, AstraZeneca, and Abbvie during the writing of this review.
  © The Royal College of Psychiatrists 2015. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence.
authors.affiliation: , MBBS, MPsych, Department of Psychiatry, University of Melbourne, Melbourne, Australia.
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Lieblich
authors.affiliation: , MD, FRANZCP, St Vincent's Hospital Melbourne and The University of Melbourne and Faculty of Health Sciences, Australian Catholic University, Melbourne, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Castle
authors.affiliation: , MD, MRCPsych, FRANZCP, Melbourne Neuropsychiatry Centre, The University of Melbourne and Melbourne Health and Florey Institute for Neuroscience & Mental Health, Melbourne, Australia, and Bedfordshire Centre For Mental Health Research in Association with the University of Cambridge, UK.
authors.forename: Christos
authors.initials: C
authors.lastname: Pantelis
authors.affiliation: , MD, FRANZCP, Professorial Psychiatry Unit, Albert Road Clinic, and University of Melbourne, Melbourne, Australia.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Hopwood
authors.affiliation: , Centre for Affective Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
authors.forename: Allan Hunter
authors.initials: AH
authors.lastname: Young
authors.affiliation: , BSc (Hons), MB ChB (Hons), PhD, DSc, FRCPsych, FRANZCP, FRCPath, Department of Psychiatry, University of Melbourne, Melbourne, Australia.
authors.forename: Ian P
authors.initials: IP
authors.lastname: Everall