Does Dual-Task Gait Differ in those with Late-Life Depression versus Mild Cognitive Impairment?

Abstract

To compare the dual-task gait performance of older adults with Late-Life Depression (LLD) versus Mild Cognitive Impairment (MCI). Cross-sectional study with three matched groups: LLD, MCI and non-depressed and cognitively intact (NDCI). LLD group participants were recruited from geriatric psychiatry clinics in London, Ontario. Matched participants meeting criteria for the MCI or NDCI groups were previously recruited for other research studies from geriatric clinics and the community. Individuals aged 60-85 who met criteria for mild-moderate LLD (N=23) without a diagnosis of a neurocognitive disorder. Participants completed questionnaires regarding mood, cognition and physical activity. Gait speed was recorded using an electronic walkway during simple and dual-task gait (walking while naming animals aloud). Dual-task cost (DTC) is the percentage change in gait speed between simple and dual-task gait. It is a clinically relevant indicator of fall risk and is strongly associated with cognitive decline. For comparison, 23 MCI and 23 NDCI participants, matched with respect to age, sex and comorbidities, were randomly selected from existing research databases. Each group had 8 males and 15 females, with mean age of 69.0-69.6 years. The mean (±SD) DTC of the NDCI, LLD and MCI groups were statistically different at 2.4±11.4%, 11.8±9.9% and 22.2±16.7%, respectively. Older adults with LLD perform worse on dual-task gait than NDCI; however, they are less impaired than those with MCI. The elevated DTC seen in LLD is likely because of underlying executive dysfunction that is less significant than in those with MCI.