Fatigue, depression and sleep disturbances in Iranian patients with multiple sclerosis

Fatigue is one of the most frequent symptoms in patients with multiple sclerosis (MS) and it is difficult to clarify the nature of this symptom and manage it. This study was aimed to evaluate the frequency of fatigue, depression and sleep disturbances in Iranian patients with MS. 100 patients from the outpatient MS clinic of Sina hospital were asked to complete Beck Depression Inventory (BDI), Pittsburg Sleep Quality Index (PSQI), Sleep Disorder Questionnaire (SDQ), Modified Fatigue Impact Scale (MFIS) and Epworth Sleepiness Scale (ESS) questionnaires. Student's t-test, ANOVA, Spearman correlation and Stepwise multiple linear regressions by SPSS version 15.0 were used for data analysis. From participants, 64 had fatigue complaint during day time and 36 did not feel fatigued. BDI, PSQI, MFIS and SDQ scores were significantly higher in fatigued patients than non-fatigued group but there were no statistically significant differences in ESS, EDSS and duration of disease between fatigued and non-fatigued cases. There were significant correlations between MFIS and BDI scores (r=0.49, P=0.01), MFIS and PSQI scores (r=0.399, P=0.01) and MFIS and ESS (r=0.25, P=0.01). This study demonstrates that depression is not the only cause of fatigue in patients with MS and it is also associated with sleep disorders, so this complaint should be carefully evaluated and managed in these patients.