Among elderly people in general, better physical function is associated with lower incidence of depressive symptoms. It is also related to better mental health, quality of life and well-being | BMJ Open

Objectives: The primary aim of this study is to describe depression and physical function in nursing home residents with dementia, as well as to examine the associations between depression and balance function, lower limb muscle strength, mobility and activities of daily living. The secondary aim is to examine the differences in physical function between the groups classified as depressed and not depressed.
Results: Nursing home residents with dementia are a heterogeneous group in terms of physical function and depression. By applying the recommended cut-off of 8 on CSDD, 23.5% of the participants were classified as being depressed. The results revealed significant associations between higher scores on CSDD (indicating more symptoms of depression) and lower scores on BBS (95% CI −0.12 to −0.02, p=0.006), 30 s CST (95% CI −0.54 to −0.07, p=0.001) as well as maximum walking speed (95% CI −4.56 to −0.20, p=0.003) (indicating lower level of physical function).
Conclusion: Better muscle strength, balance and higher walking speed were significantly associated with less depressive symptoms. The potential interaction of dementia with poor physical function and depression indicates an area to explore in future epidemiological studies with a prospective design.
Full reference: Kvæl, L.A.H. et al. (2017) Associations between physical function and depression in nursing home residents with mild and moderate dementia: a cross-sectional study. BMJ Open. 7:e016875.