Dementia And Delirium
Delirium and dementia are two frequent causes of cognitive impairment among older adults and have a distinct, complex and interconnected relationship. Delirium is an acute confusional state characterized by inattention, cognitive dysfunction and an altered level of consciousness, whereas dementia is an insidious, chronic and progressive loss of a previously acquired cognitive ability. People with dementia have a higher risk of developing delirium than the general population, and the occurrence of delirium is an independent risk factor for subsequent development of dementia. Furthermore, delirium in individuals with dementia can accelerate the trajectory of the underlying cognitive decline. Delirium prevention strategies can reduce the incidence of delirium and associated adverse outcomes, including falls and functional decline. Therefore, delirium might represent a modifiable risk factor for dementia, and interventions that prevent or minimize delirium might also reduce or prevent long-term cognitive impairment. Additionally, understanding the pathophysiology of delirium and the connection between delirium and dementia might ultimately lead to additional treatments for both conditions. In this Review, we explore mechanisms that might be common to both delirium and dementia by reviewing evidence on shared biomarkers, and we discuss the importance of delirium recognition and prevention in people with dementia.
What are the symptoms of delirium?
If someone suddenly develops any of the symptoms below or is ‘not themselves’, speak to a nurse or doctor immediately. Family, friends and carers – including professional carers – are often best placed to recognise and describe changes because they know the person best. A person with delirium may be unaware of the changes and will often be unable to describe them.
A person with delirium may:
- be easily distracted
- be less aware of where they are or what time it is (disorientation)
- suddenly not be able to do something as well as normal (for example, walking or eating)
- be unable to speak clearly or follow a conversation
- have sudden swings in mood
- have hallucinations – seeing or hearing things, often frightening, that aren’t really there
- have delusions or become paranoid – strongly believing things that are not true, for example that others are trying to physically harm them or have poisoned their food or drinks.