Title {1}	Antidepressant for the prevention of depression following first-episode psychosis (ADEPP): study protocol for a multi-centre, double-blind, randomised, controlled trial.
Trial registration {2a and 2b}.	ISRCTN12682719 registration date 24/11/2020
Protocol version {3}	V11.0, 07/12/2022
Funding {4}	NIHR award NIHR127700 This project is funded by the National Institute for Health Research (NIHR) Health Technology Assessment Programme (project reference 127,700). The Funder of the trial has had no role in the trial design, data collection, data analysis or data interpretation. MB and DG are supported by the NIHR Applied Research Collaboration (ARC) West Midlands. The study also acknowledges support by the NIHR Oxford Health Biomedical Research Centre. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.
Author details {5a}	1Institute for Mental Health, School of Psychology, University of Birmingham, Birmingham, United Kingdom 2Birmingham and Solihull Mental Health Foundation Trust, Birmingham, United Kingdom 3Early Intervention Service, Birmingham Women’s and Children’s NHS Trust, Birmingham, United Kingdom 4Birmingham Clinical Trials Unit, University of Birmingham, Birmingham, United Kingdom 5Institute of Applied Health Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom 6Hereford and Worcestershire Health and Care NHS Trust, Worcester, United Kingdom 7Division of Psychology and Mental Health, University of Manchester, Manchester, United Kingdom 8Mersey Care NHS Foundation Trust, Merseyside, United Kingdom 9Early Intervention Service Flyde and North, Lancashire and South Cumbria NHS Foundation Trust, Preston, United Kingdom 10Institute of Mental Health, Division of Mental Health and Neurosciences University of Nottingham, Nottingham, United Kingdom 11Nottinghamshire Healthcare National Health Service Foundation Trust, Nottingham, United Kingdom 12Division of Health Sciences, Warwick Medical School, University of Warwick, Warwick, United Kingdom 13Institute of Clinical Sciences. College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom 14Centre for Neuropsychiatric Genetics and Genomics, Division of Psychological Medicine and Clinical Neurosciences, Cardiff University, Cardiff, Wales, United Kingdom 15Division of Psychiatry, Imperial College London, London, United Kingdom 16Department of Health and Wellbeing, University of Warwick, Warwick, United Kingdom RU is Chief Investigator; and conceived the study, led the proposal and protocol development. TREB, MB, JTW, NH, NM and BCTU contributed to grant funding and study design. RD joined as co-lead in 2023. RD, EP, TW, RO, BW, SP and RU drafted the manuscript. All authors approved the final manuscript.
Name and contact information for the trial sponsor {5b}	Research Support Group – Research Governance Block B – Room 106 Aston Webb Building Edgbaston Birmingham B15 2TT http://www.researchgovernance@contacts.bham.ac.uk
Role of sponsor {5c}	The sponsor provided peer review of funding application. The sponsor has no role in the management, analysis, or interpretation of the data; writing of this report; and the decision to submit the report for publication.