Background: Over the years, a number of non-medical and psychosocial explanations and models of dementia have been proposed, due to the complex nature of the illness. However, there is a need for a more pragmatic, user-friendly model which takes into account the biological, psychological and social processes.
Methods: Existing models of dementia were amalgamated into a revised, pragmatic model which aims to increase our understanding of the factors that may lead to improvement or deterioration in dementia and to illustrate the role of psychosocial factors in the context of biological processes. The model suggests that in both psychosocial and biological domains there are fixed factors (aspects which relate to history or risk factors and therefore not amenable to change), tractable factors (aspects which may be amenable to change), and interventions with potential benefit.
Results: The trajectory of dementia is presented as a process, beginning with aging and ending in death. Both the fixed and the tractable factors may influence the severity of dementia, affecting function, the speed and nature of the deterioration, and the appropriateness and effectiveness of interventions. A working case example is provided, demonstrating how the model may be used by clinicians when assessing the difficulties of an individual with dementia and identifying ways to improve the quality of life and reduce excess disability for that person.
Conclusions: This model provides a theoretical framework and an ambitious approach to care in dementia which takes into account positive as well as negative factors. We hope it may become a useful tool for researchers and clinicians to help understand what impacts on individuals with dementia and the most appropriate ways to intervene.