Identifying Delirium in Persons With Moderate or Severe Dementia: Review of Challenges and an Illustrative Approach

Tamara G. Fong, Tammy T. Hshieh, Patricia A. Tabloski, Eran D. Metzger, Franchesca Arias, Hannah L. Heintz, Regan E. Patrick, Maria I. Lapid, Eva M. Schmitt, David G. Harper, Brent P. Forester, Sharon K. Inouye

Research output: Contribution to journalArticlepeer-review


Delirium and dementia are common causes of cognitive impairment among older adults, which often coexist. Delirium is associated with poor clinical outcomes, and is more frequent and more severe in patients with dementia. Identifying delirium in the presence of dementia, also described as delirium superimposed on dementia (DSD), is particularly challenging, as symptoms of delirium such as inattention, cognitive dysfunction, and altered level of consciousness, are also features of dementia. Because DSD is associated with poorer clinical outcomes than dementia alone, detecting delirium is important for reducing morbidity and mortality in this population. We review a number of delirium screening instruments that have shown promise for use in DSD, including the 4-DSD, combined Six Item Cognitive Impairment Test (6-CIT) and 4 'A's Test (4AT), Confusion Assessment Method (CAM), and the combined UB2 and 3D-CAM (UB-CAM). Each has advantages and disadvantages. We then describe the operationalization of a CAM-based approach in a current ECT in dementia project as an example of modifying an existing instrument for patients with moderate to severe dementia. Ultimately, any instrument modified will need to be validated against a standard clinical reference, in order to fully establish its sensitivity and specificity in the moderate to severe dementia population. Future work is greatly needed to advance the challenging area of accurate identification of delirium in moderate or severe dementia.

Original languageEnglish (US)
Pages (from-to)1067-1078
Number of pages12
JournalAmerican Journal of Geriatric Psychiatry
Issue number10
StatePublished - Oct 2022


  • Advanced dementia
  • ECT
  • delirium
  • delirium superimposed on dementia

ASJC Scopus subject areas

  • Geriatrics and Gerontology
  • Psychiatry and Mental health


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