Do depressive symptoms affect balance in older adults with mild cognitive impairment? Results from the "gait and brain study"

Background: Mild cognitive impairment (MCI) and depression independently affect balance control in older adults. However, it is uncertain whether depressive symptoms would amplify balance problems in older adults with MCI. Aim: To evaluate if the presence of significant depressive symptoms affects postural sway under somatosensory challenges in a MCI population. Methods: Eighty two participants (mean of 75.3 +/- 6.4 years of age; 46% women) with MCI completed cognitive and balance assessments. Participants were grouped by severity of depressive symptoms using the Geriatric Depression Scale-15, as MCI with depressive symptoms (MCI-D = 14, score >= 5) and MCI without depressive symptoms (MCI = 68, score < 5). Postural sway area was evaluated during eyes open (EO) and eyes closed (EC) while standing on a rigid flat force plate platform, and compared across groups. Analyses were controlled for age, sex, comorbidities, anti-depressant medication use, executive function, and baseline sway. Results: MCI-D showed larger postural sway area when compared with MCI irrespective of visual feedback conditions (p = 0.03). This difference remained significant after adjusting for anti-depressant use and executive function performance. The lack of interaction between groups and visual condition was associated with group differences in postural sway during EO condition (Beta = 0.08, CI - 257.5-621.9; p = 0.41) and by comparable sway increase from EO to EC in both groups. Conclusion: Depressive symptoms in individuals with MCI worsened postural stability during both eyes open and eyes closed conditions independently of cognitive function. Significant depressive symptoms may affect balance in MCI populations, potentially increasing the risk of falls.