Slowed gait is one of the strongest predictors of fall risk in older adults. The present study investigated whether gait speed mediated the relationship between depression and fall history in 147 older adults presenting to a memory clinic for cognitive complaints. Depression, cognitive status, gait speed, and number of falls within the last year were the primary measures. Results revealed fallers, relative to non-fallers, had slower gait speed and higher depression scores. As hypothesized, analyses using the PROCESS macro found that gait mediated the relationship between depression and fall history. Additionally, the combination of depression and mild cognitive impairments (MCI) associated with a significantly greater likelihood of falling. Our findings indicate that combined depression and MCI have additive effects on fall risk, likely through the destabilizing effect of slowed gait on balance. Better understanding the underlying pathophysiology involved in MCI and depression-related gait disturbances may lead to improved intervention targets for fall risk prevention.
Keywords: Cognitive decline; dementia; executive function; fall risk; pathophysiology; personalized medicine.