Depressive symptoms in older adults at risk for dementia: exploring key modifiable risk factors, the importance of physical activity, and the effects of a home-based exercise and psycho-education intervention

Abstract

Dementia is currently the leading cause of disability in older Australians, and the number of individuals living with dementia is expected to increase exponentially between now and 2050. In the absence of an effective and disease-modifying treatment for dementia, there has been a focus on preventative and early intervention strategies for older adults experiencing cognitive impairment. Many of these strategies are aimed at key modifiable risk factors for dementia, such as smoking, depression, social isolation, physical inactivity, and cardiometabolic diseases. Clinically significant depressive symptoms affect up to 36% of older adults globally. Cognitively impaired older adults experiencing depressive symptoms are likely to present with high rates of morbidity, premature mortality, disability, and poor quality of life. Furthermore, persistent depression can contribute to further cognitive decline as well as accelerating the progression to dementia in people with mild cognitive impairment. This thesis contributes to the understanding of key factors that should be considered when managing depressive symptoms in older adults with cognitive impairment, and highlights the importance of acknowledging sub-threshold depressive symptoms in this population. Furthermore, the presented evidence for the link between physical activity and depressive symptoms suggests that regular exercise needs to be routinely discussed with older adults attending memory clinics. Lastly, it is important the individualised exercise is prescribed, delivered and monitored by an exercise professional who is equipped with the skills necessary to work effectively with older adults experiencing cognitive difficulties. Ultimately, the research in this thesis encourages a holistic and multi-disciplinary approach to managing depressive symptoms and associated risk factors in older adults with cognitive impairment.