Attachment and post-traumatic stress disorder in french military personnel: characterization and exploration of biopsychosocial factors — the at-home study protocol

Introduction: In military service members, post-traumatic stress disorder (PTSD) often becomes chronic, with symptoms that significantly interfere with daily life and social functioning. These difficulties pose a major challenge for the rehabilitation and professional reintegration of injured service members. Our protocol describes a study that investigates emotional contagion processes in military personnel with PTSD, in relation to attachment style, along with selected biophysiological and psychosocial factors. Method: The method compares two groups of French military personnel: one group with PTSD (n = 41) and a control group without PTSD (n = 53). During a single visit, each participant completes four steps: (1) provision of informed consent; (2) saliva collection (for the assay of oxytocin and vasopressin, and for genetic polymorphism analyses); (3) a computer-based emotion recognition task combined with physiological recordings of electrodermal activity and heart rate variability; and (4) completion of a set of validated self-report questionnaires measuring attachment, emotional contagion, empathy, post-traumatic symptoms, stress, adverse childhood experiences, and positive mental health; and a set of sociodemographic questions gathering information on participants' personal and professional background. Ethics: Ethical approval has been obtained from the Sud-Est VI Ethics Committee (reference no 25.0555.000354, 14/03/2025). Trial registration number: ClinicalTrials.gov identifier: NCT06996275.