The proportion of ED visits by older adults is expected to continue its rapid increase over the coming decades.1 As a result, we can expect to see many patients who present for, or present with, mental health disorders. In 2013, the American Psychiatric Association released the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders,2 in which they introduced the terms mild and major neurocognitive disorder, the latter of which was previously called dementia. We will continue to use the term dementia to represent major neurocognitive disorder in this chapter. Delirium, dementia, and depression affect many older adults, and the differentiation of these disorders can be challenging because they are interrelated. Patients with dementia are more likely to develop delirium,3 and patients who experience delirium are more likely to develop dementia later in life.4-7
It can also be difficult to diagnose depression in patients with dementia, as both disorders can demonstrate similar symptoms such as apathy and behavioral changes.8 Also, depression in late life has been associated with an increased risk of developing dementia, further demonstrating that dementia, delirium, and depression are interconnected, increase the risk of each other, and are all associated with an increased risk of mortality and morbidity.9-15 Table 288-1 provides distinguishing features of delirium, dementia, and psychiatric disorders. Chapter 168, “Altered Mental Status and Coma,” and Chapter 286, “Mental Health Disorders: ED Evaluation and Disposition,” also discuss the distinctions between delirium, minor neurocognitive disorder, and psychiatric disorders.
TABLE 288-1Features of Delirium, Dementia, and Psychiatric Disorder |Favorite Table|Download (.pdf) TABLE 288-1 Features of Delirium, Dementia, and Psychiatric Disorder
|Characteristic ||Delirium ||Dementia ||Psychiatric Disorder |
|Onset ||Over days ||Insidious ||Varies |
|Course over 24 h ||Fluctuating ||Stable ||Varies |
|Consciousness ||Reduced or hyperalert ||Alert ||Alert or distracted |
|Attention ||Disordered ||Normal ||May be disordered |
|Cognition ||Disordered ||Impaired ||Rarely impaired |
|Orientation ||Impaired ||Often impaired ||May be impaired |
|Hallucinations ||Visual and/or auditory ||Often absent ||May be present |
|Delusions ||Transient, poorly organized ||Usually absent ||Sustained |
|Movements ||Asterixis, tremor may be present ||Often absent ||Varies |
Finally, the management of acute delirium, psychosis, or behavioral disturbances in older adults in the ED can be difficult. Medications such as benzodiazepines and antipsychotics, which are frequently used in younger agitated patients, may have significant side effects in older patients, such as prolonged sedation, or paradoxical agitation with benzodiazepines. Medications for acute agitation should be selected carefully and typically at lower doses than for younger patients, and should only be used after nonpharmacologic modifications and interventions have been exhausted.
Delirium is an acute change in cognition that fluctuates rapidly over time and is often reversible. Delirium is frequently the first sign of an underlying acute medical illness. Patients demonstrate altered levels of consciousness, inattention, disorganized thinking, and altered perception. There are three main types ...