Fatigue, depression and disability accumulation in multiple sclerosis: a cross-sectional study

To investigate the influence of disability and the speed of disability accumulation on fatigue and depression in a large cohort of patients with multiple sclerosis (MS). A total of 412 patients completed the Fatigue Severity Scale (FSS) and Center for Epidemiological Studies Depression Scale (CESD). The patients were registered at our outpatient department and demographic and disease specific data were compared between patients with and without severe fatigue (FSS >= 5.0) and clinically significant depressive symptoms (CESD >= 16). We investigated the association of Expanded Disability Status Scale (EDSS) scores, multiple sclerosis severity scores (MSSS) and either CESD scores or FSS-scores with severe fatigue and clinically significant depressive symptoms in a multivariable logistic regression model, with adjustment for possible confounders. Only CESD scores were independently associated with severe fatigue. FSS scores and female gender were independently associated with clinically significant depressive symptoms. Neither EDSS nor MSSS scores were independently associated with fatigue or depression. In patients with MS, fatigue and depression are strongly associated with each other but not with the degree of disability or the speed of disability accumulation.