About the Authors

Sean P. Grant

sean.grant@spi.ox.ac.uk

Affiliation Centre for Evidence-Based Intervention, University of Oxford, Oxford, United Kingdom

Evan Mayo-Wilson

Affiliation Centre for Outcomes Research and Effectiveness, Research Department of Clinical, Educational & Health Psychology, University College London, London, United Kingdom

G. J. Melendez-Torres

Affiliation Centre for Evidence-Based Intervention, University of Oxford, Oxford, United Kingdom

Paul Montgomery

Affiliation Centre for Evidence-Based Intervention, University of Oxford, Oxford, United Kingdom

Competing Interests

SG, EMW, and PM are currently involved in the development of a CONSORT extension for social and psychological interventions (http://www.tinyurl.com/CONSORT-study). This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: SG EMW PM. Performed the experiments: SG GJMT. Analyzed the data: SG EMW PM. Wrote the paper: SG EMW GJMT PM.