Cognitive impairment has a strong relation to nonsomatic symptoms of depression in relapsing-remitting multiple sclerosis

It is unclear how cognitive impairment in multiple sclerosis (MS) is influenced by physical disability, fatigue, and depression. Our aim was to identify the strongest clinical predictors for cognitive impairment in relapsing-remitting MS (RRMS) patients. The clinical risk factors included in the analysis were physical disability (EDSS), fatigue (FSS), the somatic and nonsomatic components of depression (BDI), disease progression rate [Multiple Sclerosis Severity Score (MSSS)], and psychotropic medication. Cognitive impairment had a prevalence of 30.5 % in patients affecting preferentially attention, executive functions, processing speed and visual perception/organization. MSSS was not associated with cognitive impairment, depression, or fatigue. In regression models, cognitive performance was best predicted by the non-somatic symptoms of depression alone or in combination with physical disability. Exclusion of patients with any psychotropic medication did not influence the results. Our results underscore the importance of evaluating depressive symptoms when suspecting cognitive impairment in patients with RRMS