Associations between pain and depression in nursing home patients at different stages of dementia

Abstract

Background: Pain is associated with depression in nursing home patients with dementia. It is, however, unclear whether pain increases depression. Therefore we evaluated the prospective associations between pain and depressive symptoms in nursing home patients at different stages of cognitive impairment.

Methods: Two longitudinal studies were combined, including 931 patients (≥65 years) from 65 nursing homes. One study assessed patients at admission, with 6-month follow-up (2012-2014). The other study assessed residents with varying lengths of stay, with 4-month follow-up (2014-2015). Patients were assessed with the Mini-Mental State Examination, the Mobilisation-Observation-Behaviour-Intensity-Dementia-2 Pain Scale, and the Cornell Scale for Depression in Dementia.

Results: At baseline, 343 patients (40% of 858 assessed) had moderate to severe pain, and 347 (38% of 924) had depression. Pain increased the risk of depression (OR 2.35, 95% CI 1.76-3.12). Using mixed model analyses, we found that a 1-point increase in pain was associated with a .48 increase in depression (p<.001). This association persisted in mild, moderate, and severe cognitive impairment. In those recently admitted, depressive symptoms decreased over time, and having less pain at follow-up was associated with a decrease in depressive symptoms (within-subject effect; p=.042).

Limitations: The two cohorts had different inclusion criteria, which may reduce generalisability. The study design does not allow conclusions on causality.

Conclusions: Pain and depressive symptoms are associated in patients with dementia. Because reduced pain is associated with less depressive symptoms, these patients should be assessed regularly for untreated pain. The benefit of analgesic treatment should be weighed carefully against the potential for adverse effects.

Keywords: Dementia; Depression; Nursing home; Pain.