Depressive symptoms and fatigue are independently associated with myasthenia gravis-specific quality of life beyond neurological severity: a cross-sectional study

Abstract

Neurological examination and myasthenia gravis (MG)-specific functional scales may not fully capture the psychological and fatigue-related burden of MG. This cross-sectional registry-based study included 75 adults with MG. Depressive and anxiety symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) with validated Latvian- and Russian-language thresholds. Fatigue, quality of life, functional impairment and clinical severity were assessed using the Fatigue Severity Scale (FSS), 15-item Myasthenia Gravis Quality of Life Questionnaire (MG-QOL15), Myasthenia Gravis Activities of Daily Living (MG-ADL) and MG Composite Score (MGCS). Analyses included group comparisons, Spearman correlations, and exploratory multivariable linear regression. Positive depression and anxiety screens were identified in 32/75 (42.7%) and 38/75 (50.7%) patients using language-specific thresholds, compared with 25/75 (33.3%) and 18/75 (24.0%) using conventional thresholds, despite low-to-moderate disease activity (median MGCS 3; MG-ADL 1). Depressive symptoms were associated with poorer MG-QOL15, higher MGCS, greater functional impairment and higher anxiety scores, whereas anxiety correlated only weakly with MG-QOL15 (rho = 0.270). Neurological severity alone may underestimate patient-perceived disease burden. Depressive symptoms and fatigue contribute independently to MG-specific quality of life beyond conventional clinical severity assessment, supporting psychological and fatigue screening even in patients with apparent clinical stability.