The relationship between quality of life, depression and cognitive function in patients with multiple sclerosis

Objective: Cognitive impairment, which is one the most common findings associated with multiple sclerosis (MS), is one of the leading causes disability in MS. The prevalence of cognitive impairment is estimated to be 43-70% in early and late phase of the disease. Depression may be seen in over half of patients with MS at any time during their disease. Depressive symptoms adversely affect cognition and make difficult to cope with the disease. Deficits of cognitive function and depressive symptoms are related with low quality of life. The purpose of the current study is to investigate the corelation between quality of life, depression and cognitive function and to compare cognitive function levels of MS patient and healthy controls. Methods: Eighty-two RRMS patient who admitted to the EU department of neurology clinic were determined to comply with the inclusion criteria and 82 age and gender matched healthy control participants were enrolled in this study. Cognitive function was assessed with "Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS)" battery, depression was assessed with "Beck Depression Inventory (BDI)" and quality of life was assessed with "MS International Quality of Life questionnaire (MUSIQoL)" in MS group. BICAMS battery was used to identify cognitive function status of healthy controls and BDI was to identify their depression levels. BICAMS battery contains SDMT, which is evaluate information processing speed, CVLT-II, which is evaluate verbal learning and memory, and BVMT-R which evaluates visual memory. Results: There was a significant difference between MS group and healthy control group according to SDMT, CVLT-II and BVMT-R (p<0,05), while no difference according to BDI (p>0,05). There was no significant correlation between MUSIQoL subscales and BICAMS battery (p>0,05). A significant negative weak correlation was found between SDMT and BDI; CVLT-II and BDI (r=-0,240; r=-0,231; p<0,05), negative moderate correlate was found between BVMT-R and BDI (r=-0,267; p<0,05). There was no significant correlation between MUSIQoL and BDI (r=0,488; p<0,001). A significant correlation was found between EDSS and FAS with BICAMS battery (r=-0,311, r=-0,235, r=-0,256; p<0,05)(r=0,360, r=0,317, r=0,280; p>0,05), but only correlation between disease duration and SDMT test (r=-0,318; p<0,01). A statistically significant correlation was found between education level and cognitive function in both MS and healthy control groups (r=0,572, r=0,311, r=0,429; p<0,01)(r=0,719, r=0,579, r=0,619; p<0,001). Conclusion: The result of our study shows that MS patients performed significantly worse in BICAMS battery than the members of the healthy control group. In addition, there is a correlation between cognitive function and depression. Also the lack of significant correlation between cognitive function and quality of life shows discordance with previous studies. This situation can be explained by the fact that the aging of the cases in our study is young and the duration of the disease is short.