Protocol for a Multicenter Observational Study on Fatigue Across Physical–Mental Conditions within the German Center for Mental Health

Rebecca Sarah Erschens^1,2*Stephan Zipfel^1,2Marissa Bentele^1,2Sophia Helen Adam¹Carla Schröpel¹Henrik Heitmann^3,4Marius Binneböse^5,6Verena Zimmermann-Schlegel^7,8Julian Reichert^7,9Caroline Rometsch¹Isabel Ottlewski^10,11Anna Schappert^10,11Hans-Christoph Friederich^7,8Harald Gündel^12,13Matthias Rose^10,11Jonas Tesarz^7,9Florian Junne^5,6Peter Henningsen^3,4Andreas Stengel^1,14

• ¹University Hospital Tübingen, Department of Psychosomatic Medicine and Psychotherapy, Tübingen, Germany
• ²German Center for Mental Health (DZPG), Tübingen Site, Tübingen, Germany
• ³Klinikum rechts der Isar, Technical University of Munich, Department and Outpatient Clinic of Psychosomatic Medicine and Psychotherapy, Munich, Germany
• ⁴German Center for Mental Health (DZPG), Munich/Augsburg Site, Munich, Germany
• ⁵University Hospital Magdeburg, Department of Psychosomatic Medicine and Psychotherapy, Magdeburg, Germany
• ⁶German Center for Mental Health (DZPG), Jena/Halle/Magdeburg Site, Magdeburg, Germany
• ⁷University Hospital Heidelberg, Department of General Internal Medicine and Psychosomatics, Heidelberg, Germany
• ⁸German Center for Mental Health (DZPG), Mannheim/Heidelberg/Ulm Site, Heidelberg, Germany
• ⁹University Medical Center Mainz, Department and Outpatient Clinic of Psychosomatic Medicine and Psychotherapy, Mainz, Germany
• ¹⁰Charité – Universitätsmedizin Berlin, Department of Psychosomatic Medicine, Berlin, Germany
• ¹¹German Center for Mental Health (DZPG), Berlin/Potsdam Site, Berlin, Germany
• ¹²German Center for Mental Health (DZPG), Mannheim/Heidelberg/Ulm Site, Ulm, Germany
• ¹³University Hospital Ulm, Department of Psychosomatic Medicine and Psychotherapy, Ulm, Germany
• ¹⁴Clinic of Psychosomatic Medicine and Psychotherapy, Klinikum Stuttgart, Stuttgart, Germany

ABSTRACT Introduction Fatigue is a common and debilitating symptom across a wide range of chronic physical and mental health conditions. It affects physical, cognitive, and emotional functioning and substantially reduces quality of life. Despite its clinical relevance, fatigue research remains largely diagnosis-specific, resulting in limited understanding of cross-diagnostic patterns and the interplay between somatic, psychological, and psychosocial factors. Comparative data spanning different physical and mental health conditions remain limited. Objectives This multicentre, cross-sectional observational study is designed to characterise the multidimensional profile of fatigue across seven diagnostic cohorts representing metabolic, inflammatory, oncological, neuroimmunological, post-infectious, and functional-psychosomatic conditions included in the framework of the German Center for Mental Health. Methods and Analysis Participants will complete a standardised psychometric assessment battery assessing fatigue severity, post-exertional malaise, physical functioning, and related mental-health and psychosocial variables. Key domains include depressive and anxiety symptoms, somatisation, trauma history, pain, work ability, and occupational stress. Data will be analysed descriptively and comparatively to examine shared versus condition-specific fatigue patterns within a bio-psycho-social framework. Ethics and Dissemination Ethical approval has been obtained from all participating centres prior to the conduct of the study procedures described herein, and the study is registered in the German Clinical Trials Register (DRKS00037687). Findings will be disseminated through peer-reviewed publications, conference presentations, and stakeholder networks of the German Center for Mental Health.