Depression Severity, but Not Cognitive Impairment or Frailty, is Associated with Disability in Late-Life Depression

Objectives: Assess the relationship of cognitive impairment to disability, accounting for depression severity and frailty, among older adults with late-life depression (LLD). Methods: Data were analyzed from 78 community-dwelling older adults with LLD and without dementia (age M = 71.9; SD = 6.1). Cognitive functioning was assessed using a comprehensive neuropsychological battery. Depression severity was measured using the 17-item Hamilton Depression Rating Scale (HDRS; cutoff >= 15). Frailty was assessed using several motor tests. The World Health Organization Disability Assessment Schedule (WHO-DAS) measured disability status. A linear regression analysis was performed to identify relationships of cognition, frailty and depression severity with disability. Results: The average number of impaired cognitive tests was 2.0 (SD = 1.9), with 28.2% of participants showing no impaired scores. On average participants reported depression severity of 17.3 (SD = 3.6), and disability total score of 15.1 (SD = 6.9). The regression model accounted for 25.1% of the variance in disability, with only depression severity significantly predicting disability status. Burden of cognitive impairment and frailty were not predictive of disability in this sample. Conclusions: In this sample, only depression severity was associated with increased disability.