1. Altman DG, Bland MJ (1994) Diagnostic tests 2: predictive values. BMJ 309:102
2. American Psychiatric Association (2000) Diagnostic and statistical manual of mental disorders, text revision (DSM-IV-TR), 4th edn. American Psychiatric Association, Washington DC
3. Andrews G, Sanderson K, Corry J, Lapsley HM (2000) Using epidemiological data to model efficiency in reducing the burden of depression. J Mental Health Policy Econ 3:175–186
4. Becker LA, Oxman AD (2009) Overviews of reviews [Chapter 22]. In: Higgins JPT, Green S (eds) Cochrane handbook for systematic reviews of interventions, version 5.0.2 [updated Sept 2009] The Cochrane Collaboration, 2009. Available from http://www.cochrane-handbook.org
5. Centre for Reviews & Dissemination (2009) York, University of York. Available from http://www.crd.york.ac.uk/crdweb/html/help.htm