Peer support based on Mental Health First Aid for medical residents in Lyon, France: protocol for a non-randomised controlled mixed-methods study.

INTRODUCTION

Medical residents frequently experience anxiety, depression, burnout and suicidal ideation. Existing support strategies have shown limited benefit. The Impact de la Pair-Aidance Étudiante sur la Santé Mentale des internes de Médecine de première année (PAESSM) study will evaluate whether embedding Mental Health First Aid (MHFA)-trained peer supporters within a first-year residency cohort is associated with improved mental well-being and reduced psychological distress over 12 months.

METHODS AND ANALYSIS: PAESSM is a non-randomised controlled mixed-methods quasi-experimental study in Lyon, France involving the two Lyon medical schools. Two contemporaneous cohorts will be followed for 12 months: first-year residents exposed to a structured peer-support programme and second-year residents receiving usual support resources without a structured peer-support network. About 430 residents are eligible in each cohort, with anticipated enrolment of approximately 260 per group. In the intervention cohort, around 10% of first-year residents will complete certified MHFA training and act as peer supporters. Online questionnaires will be administered at baseline and at 3, 6, 9 and 12 months. The primary outcome is 12-month mental well-being measured by the Warwick-Edinburgh Mental Well-Being Scale. Secondary outcomes include anxiety and depression symptoms, suicidal ideation, job strain and help-seeking behaviours. The primary analysis will use longitudinal targeted maximum likelihood estimation adjusted for prespecified baseline covariates and informative censoring. Sensitivity analyses will include mixed-effects models and complete-case analyses. A qualitative sub-study will explore peer supporters' experiences and implementation processes.

ETHICS AND DISSEMINATION: Ethical approval was obtained from the Comité de Protection des Personnes Nord-Ouest IV (Ref: 2025-A01549-40). In accordance with French legislation applicable to minimal-risk research, formal written informed consent was waived and participants will provide documented non-opposition before inclusion. Findings will be disseminated through peer-reviewed publications, conference presentations and communication with institutional stakeholders and residents.

TRIAL REGISTRATION NUMBER: NCT07161284.