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

ABSTRACT

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.

Clinical Implications

These findings have implications for intervention in LLD, as depression severity may represent a more modifiable risk factor for disability.

KEYWORDS:

• Late life depression
• cognitive impairment
• frailty
• disability

Clinical Implications

• Older adults with major depression are at risk for functional disability related to several factors such as cognitive impairment and frailty, however the severity of depressive symptoms appears to be the most salient factor.

• In LLD populations without dementia, treating symptoms of depression may also have a positive impact on functional ability, regardless of the presence of impairments on cognitive tests.

Acknowledgments

This research is supported by the Department of Veterans Affairs Office of Academic Affiliations Advanced Fellowship Program in Mental Illness Research and Treatment, Sierra Pacific Mental Illness Research Education and Clinic Centers, San Francisco VA Medical Center, and the Department of Psychiatry, University of California, San Francisco, and National Institute of Mental Health K08 grant MH081065.

Disclosure statement

Dr. Nelson reports personal fees from Otsuka, Lundbeck, Assurex, Janssen, Eisai, Corcept, Sunovion, and UpToDate, outside the submitted work. The authors have no declarations of interest to report.

Additional information

Funding

This work was supported by the National Institute of Mental Health [MH081065].