Background: Balance impairments are common and multifactorial among people with Multiple Sclerosis (MS). Depression is the most common psychological disorder in MS population and is strongly correlated with MS disease. Depression might be one of the factors that contribute to balance deficits in this population. However, the relationship between depression and balance impairments has not been explored in people with MS. Objective: To investigate the association between depression and balance impairments in people with MS. Methods: Cross sectional design was used in patients with MS. The Activitiesspecific Balance Confidence scale (ABC) and Berg Balance Scale (BBS) was used to assess balance. Beck Depression Inventory (BDI-II) was used to quantify depression and Kurtizki Expanded Disability Status Scale (EDSS) was utilized for the evaluation of MS disability severity. Pearson correlation coefficient was used to examine the association between depression and balance measurements. Multiple linear stepwise regressions were also conducted to find out if depression is a potential predictor for balance deficits. Results: Seventy-five individuals with MS (Female=69%) with a mean age (SD) of 38.8 (10) and a mean (SD) EDSS score of 3.0 (1.4) were recruited in this study. Depression was present in 53% of the patients. Depression was significantly correlated with balance measurements and EDSS. However, multiple linear stepwise regressions found that only depression and age significantly predict balance. Conclusion: Depression and balance were found frequent and associated in people with MS. Importantly depression was a significant predictor for balance impairments in individuals with MS. Balance rehabilitation may be hindered by depression. Therefore, depression should be evaluated and treated properly in individuals with MS.

Introduction

Multiple sclerosis (MS) is estimated to affect more than 2 million people worldwide, with an estimated prevalence of 30/100,000 (National Multiple Sclerosis Society, 2017; World Health Organization, 2008). Patients with MS suffer from a wide range of impairments and limitations. These impairments include physical, neuropsychiatric and psychosocial symptoms. Physical manifestations of MS may include spasticity, cerebellar, sensory, visual, and vestibular impairments that lead to balance and gait disorders. Balance difficulties are important component for determining functional status in people with MS (Larocca, 2011). Deficits in balance usually occur early in the MS disease and typically worsen with the progression of the disease (Cavanaugh et al., 2011; Comber et al., 2017; Martin et al., 2006). Most of balance aspects were found impaired in people with MS including increased postural sway during standing (Huisinga et al., 2012; Spain et al., 2012), abnormal static and dynamic balance,(Fritz et al., 2015) and delayed postural reactions (Cameron & Lord, 2010). Several consequences were reported from poor balance in MS population including decreased physical activity, increased risk of falling and deterioration in quality of life (Klevan et al., 2014; Nilsagard, Denison, et al., 2009; Nilsagard, Lundholm, et al., 2009). Balance and walking abilities are closely related to each other (Cameron & Lord, 2010; Cattaneo et al., 2002). It is known that deficits in systems contributing to balance can impede dynamic stability during walking (Cattaneo et al., 2002; Fritz et al., 2015). It was reported that balance deficits are strong predictors of risk of falls in people with MS (Cattaneo et al., 2002; Kasser et al., 2011). Recently, researchers have attempted to investigate factors that affect balance skills and may consequently contribute to the effectiveness of rehabilitation outcomes and reduction of risk of falling. However, balance is multifactorial and several interacting factors such as cognitive impairments (Sandroff, Hillman, et al., 2015; Sandroff, Pilutti, et al., 2015) and fatigue (Van Emmerik et al., 2010; Wolkorte et al., 2015) are found to be associated with impaired balance in people with MS. Despite the fact that depression is the most common psychological impairment in patients with MS (LaRocca et al., 1987) and found to present in 54% of this population (Minden et al., 1987), research on the relationship between balance and depression specifically in patients with MS is deeply lacking.