Factors associated with depressive mood at the onset of multiple sclerosis - an analysis of 781 patients of the German NationMS cohort

Abstract

Background: Depression has a major impact on the disease burden of multiple sclerosis (MS). Analyses of overlapping MS and depression risk factors [smoking, vitamin D (25-OH-VD) and Epstein-Barr virus (EBV) infection] and sex, age, disease characteristics and neuroimaging features associated with depressive symptoms in early MS are scarce.

Objectives: To assess an association of MS risk factors with depressive symptoms within the German NationMS cohort.

Design: Cross-sectional analysis within a multicenter observational study.

Methods: Baseline data of n = 781 adults with newly diagnosed clinically isolated syndrome or relapsing-remitting MS qualified for analysis. Global and region-specific magnetic resonance imaging (MRI)-volumetry parameters were available for n = 327 patients. Association of demographic factors, MS characteristics and risk factors [sex, age, smoking, disease course, presence of current relapse, expanded disability status scale (EDSS) score, fatigue (fatigue scale motor cognition), 25-OH-VD serum concentration, EBV nuclear antigen-1 IgG (EBNA1-IgG) serum levels] and depressive symptoms (Beck Depression Inventory-II, BDI-II) was tested as a primary outcome by multivariable linear regression. Non-parametric correlation and group comparison were performed for associations of MRI parameters and depressive symptoms.

Results: Mean age was 34.3 years (95% confidence interval: 33.6-35.0). The female-to-male ratio was 2.3:1. At least minimal depressive symptoms (BDI-II > 8) were present in n = 256 (32.8%), 25-OH-VD deficiency (<20 ng/ml) in n = 398 (51.0%), n = 246 (31.5%) participants were smokers. Presence of current relapse [coefficient (c) = 1.48, p = 0.016], more severe fatigue (c = 0.26, p < 0.0001), lower 25-OH-VD (c = -0.03, p = 0.034) and smoking (c = 0.35, p = 0.008) were associated with higher BDI-II scores. Sex, age, disease course, EDSS, month of visit, EBNA1-IgG levels and brain volumes at baseline were not.

Conclusion: Depressive symptoms need to be assessed in early MS. Patients during relapse seem especially vulnerable to depressive symptoms. Contributing factors such as fatigue, vitamin D deficiency and smoking, could specifically be targeted in future interventions and should be investigated in prospective studies.

Keywords: CIS; MRI; MS; clinically isolated syndrome; cohort study; depression; neuropsychological symptoms; relapse; sex; smoking; vitamin D.

Figure 1.

Factors related to depressive symptoms. Multivariable linear regression. Dependent variable: Severity of depressive symptoms as measured by BDI-II score. Regression coefficient with 95% CI given for each parameter. p values for sex, age, MS diagnosis (CIS versus RRMS), baseline EDSS, month of sampling and EBNA1-IgG levels: >0.05, for current relapse: p = 0.016, higher severity of fatigue: p < 0.0001, less 25-OH-vitamin D: p = 0.034, current smoking: p = 0.008. Linear regression model: R: 0.449. Coding: sex: 0 – female, 1 – male; age – years; smoking: 0 – No, 1 – Occasionally, 2 – ⩽5 cigarettes per day, 3 – 6–10 cigarettes per day, 4 – 11–20 cigarettes per day, 5 – >20 cigarettes per day; diagnosis: 0 – CIS, 1 – RRMS; current relapse: 0 – No, 1 – Yes; EDSS – score; FSMC – total score; 25-OH-vitamin D serum concentration – ng/ml; month of sampling – month; EBNA1-IgG titer – U/ml. BDI-II, Beck Depression Inventory-II; CIS, clinically isolated syndrome; EBNA1-IgG, EBV nuclear antigen-1 IgG; EDSS, expanded disability status scale; FSMC, fatigue scale motor cognition; RRMS, relapsing-remitting multiple sclerosis.