Depression, motor function and cognitive function in epidemiological study

Abstract

With the striking increase in the number of elderly people in Japan, dementia has not only become a medical but also a social issue. Recently we have reported a crude prevalence of dementia in Ama-cho, a rural island town to be 16.4% in elderly people aged 65 years or older. Observational studies have identified a wide range of potentially modifiable risk factors for dementia, including cardiovascular risk factors, depression and low level of physical or mental activity. Several studies have demonstrated an association between mild parkinsonian signs (MPS) and incident dementia. We have reported a crude prevalence of subjects with MPS to be 22.1% in elderly people aged 60 years or older in Ama-cho. The actigraphic activity counts measured by Actiwatch were significantly reduced in the subjects with severe MPS-severe and a close relationship between MPS and depression was shown in this cohort. Each of depression, motor dysfunction and cognitive dysfunction might affect each other in development of dementia, and was associated with organic changes of brain accompany with modifiable risk factors for dementia. Randomized control trials of multimodal risk factor reduction strategies to prevent dementia are needed.