Impact of depression on mental fatigue and attention in patients with multiple sclerosis

Abstract

• Depression and fatigue had a great impact on cognition in patients with MS. • Patients with MS had severe fatigue and depression irrespective of disease duration. • Mental fatigue was strongly correlated with depression. • As depression became more severe, mental and physical fatigue increased. Abstract 1 1 Abbreviations BDI, Beck Depression Inventory; CFS, Chalder Fatigue Scale; EDSS, Expanded Disability Status Scale; HC, Health control subjects; MMSE, Mini-Mental State Examination MS, Multiple sclerosis; PASAT, Paced Auditory Serial Addition Test; QoL, Quality-of-life SD, Standard deviation; SDMT, Symbol Digit Modalities Test; VC, Visual cancellation; Depression and fatigue are debilitating symptoms in multiple sclerosis (MS), which affect cognitive function. This study investigated the association between depression and fatigue, and whether depression or fatigue influences cognition in MS patients. Twenty MS patients were included. The severity of fatigue was assessed using the Chalder Fatigue Scale (CFS), which classified CFS_Physical and CFS_Mental fatigue and MMSE. Depression was assessed using the Beck Depression Inventory (BDI). Attention deficit was evaluated using several tasks. The CFS scores, the BDI scores and performance during the attention tasks were compared between MS patients and healthy control subjects (HCs). Correlations between CFS sub-scores, BDI values, and participants’ attention performance were also investigated. The total CFS, BDI, and MMSE scores were significantly worse in MS patients compared to HCs ( p < 0.05). The CFS_Mental sub-score was significantly correlated with performance on attention tasks ( p < 0.05). MS patients with severe depression exhibited the worst scores on attention tests and significantly higher CFS_Mental sub-scores than the remaining MS patients and HCs. The BDI scores of MS patients with severe depression correlated with disease duration. In the remaining MS patients, attention tests and BDI scores did not differ significantly from those in HCs. This study had a small sample size, which limits generalization. Premobid cognitive functions were not matched. Mental fatigue is closely associated with attention deficit. Depression affects mental fatigue and attention in MS patients.