Wartime stress and relapse risk in people with multiple sclerosis: a prospective cohort study

Introduction: Psychological stress has been proposed as a trigger for disease activity in multiple sclerosis (MS), but findings have been inconsistent. While prior research has focused largely on chronic stressors, little is known about how people with MS (pwMS) cope with acute, large-scale stress events such as war. Objective: Examine the effects of wartime stress following the October 7, 2023 attack on disease activity in pwMS, and to assess whether emotional factors are associated with relapse risk during this period. Methods: Clinical data on relapses and disability progression were collected retrospectively for the year preceding October 7, 2023, and prospectively for the year following that date. Participants completed standardized questionnaires assessing stress, anxiety, depression, fatigue, and coping flexibility between April and June 2024. Results: From the 145 pwMS included in the prospective study, 38% experienced at least one relapse in the post-war year, compared to 23% in the year prior. Perceived fatigue was significantly higher among those who experienced relapses, while anxiety, depression, and perceived stress were not significantly associated with relapse frequency. Coping flexibility did not moderate the relationship between psychological distress and relapse count. No significant change was observed in disability progression across the two time periods. Conclusions: Wartime conditions were associated with increased relapse activity in pwMS. Fatigue may serve as a sensitive marker of disease vulnerability during stress. Coping flexibility, as measured in this study, did not appear to buffer the effects of psychological distress on relapse risk.