Fig. 1.

A hypothetical model for the interrelationship between delirium and dementia. In the setting of precipitating factors (i.e., hypoxia, infection, surgery, metabolic abnormalities, and drugs) and in the presence of underlying brain vulnerability, delirium occurs. In the presence of resilience factors, such as cognitive reserve or the implementation of multicomponent prevention strategies,^150,151 delirium does not occur. Delirium results in potentially damaging processes, such as an exaggerated stress response, further neuroinflammation, and subsequent neuronal dysfunction, injury, and cell death, leading to poor outcomes, including dementia. Dementia in turn contributes to brain vulnerability, increasing the risk of delirium.