Depression and sleep disturbances in patients with multiple sclerosis and correlation with associated fatigue

Objective: To observe prevalence of depression and sleep disturbances in multiple sclerosis (MS) patients and their correlation with associated fatigue. Study Design and Setting: Prospective observation study in a university tertiary research hospital in India. Materials and Methods: Thirty-one patients (6 male and 25 female) with definite MS (McDonald's criteria) presented in out-patient/admitted in the department of neurology (between February 2010 and December 2011) were included in the study. Depression was assessed using Beck's Depression Inventory (BDI). Sleep quality was assessed using Pittsburg Sleep Quality Index (PSQI). Disease severity was evaluated using the Kurtzke's expanded disability status scale (EDSS). Fatigue was assessed using Krupp's fatigue severity scale (FSS). We tried to observe correlation of depression and sleep disturbance with associated fatigue in MS patients. Results: The age of patients varied between 16 and 50 years (30.1 +/- 9.1). The mean age at first symptom was 25.2 +/- 6.4 years (range 14- 39 years). The prevalence of sleep disturbance and depression was 51.6% (16/31) each and fatigue 58.1% (18/31) in the study group. The PSQI scores were significantly greater in the patients with fatigue as compared with those without fatigue indicating poorer sleep quality is associated with fatigue in MS (P = 0.005). The BDI scores were also significantly higher in the fatigue group showing that severity of depression also strongly correlated with fatigue (P = 0.001). Conclusions: Depression and sleep disturbance in patients with MS is significantly correlated with associated fatigue.