Deliriumanddementiaare conditions that can be confusing, both to experience and to distinguish. Both can cause memory loss,poor judgment, a decreased ability tocommunicate, and impaired functioning. While the question of delirium vs dementia may seem difficult to answer, there are many differences between the two, including the following:
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Onset
Dementia:Dementia typically begins slowly and is gradually noticed over time. If the person who’s being evaluated is unknown to you, getting a report of their usual functioning is key.
Delirium:Delirium is usually a sudden change in a condition. One day, your loved one is doing fine, and the next, she may be very confused andunable to get dressed. Delirium is also known asacute confusional state, with the key being that it is acute, or sudden.
Cause
Dementia:The cause of dementia is typically a disease such asAlzheimer’s,vascular dementia,lewy body dementia,frontotemporal dementiaor a related disorder.
Duration
Dementia:Dementia is generally a chronic, progressive disease that is incurable. (There are some reversible causes of dementia symptoms such asvitamin B12 deficiency,normal pressure hydrocephalus, and thyroid dysfunction).
Delirium:Delirium can last for a couple of days to even a couple of months. Delirium is almost always temporary if the cause is identified and treated.
Communication Abilities
Dementia:People with dementia may have difficultyfinding the right words, and the ability to express themselves gradually deteriorates as the disease progresses.
Delirium:Delirium may significantly and uncharacteristically impair someone’s ability to speak coherently or appropriately.
Attention Span and Memory
Dementia:A person’s level of alertness is typically not affected until the late stages of Alzheimer’s, whereas memory is significantly affected throughout the disease.
Delirium:In delirium, the opposite is true. Memory functioning is usually less affected in delirium but the ability to focus and maintain attention to something or someone is very poor.
Activity Level
Dementia:Dementia tends to not affect a person’s activity level until the later stages.
Delirium:People with delirium are often either overly active (hyper and restless) or under-active (lethargic and less responsive) compared to usual functioning.
Treatment
Aduhelm Discontinued
In June 2021, the Food and Drug Administration (FDA) approved Aduhelm (aducanumab) for treating Alzheimer’s disease. It was the first drug approved for this disease since 2003 and targets amyloid-beta. However, studies showed little or no benefit in slowing cognitive decline.
What the End of Aduhelm Means for Alzheimer’s Treatment
Delirium in People With Dementia
Knowing how to identify delirium in someone who is already confused is critical for appropriate treatment and a faster recovery. Delirium superimposed on someone with dementia also is connected with a more than double mortality risk compared to those with delirium or dementia alone.
Delirium Signs to Look For
A Word From Verywell
Understanding the difference between delirium and dementia can be helpful in identifying if your loved one needs to see the doctor immediately, or if he should be evaluated at an appointment that’s scheduled within a few weeks. Be sure to report any signs of delirium, especially a sudden change in functioning or health, to the physician for evaluation and prompt treatment.
What’s the Difference Between Dementia and Alzheimer’s?
12 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Duong S, Patel T, Chang F.Dementia: What pharmacists need to know.Can Pharm J (Ott). 2017;150(2):118–129. doi:10.1177/1715163517690745The Mayo Clinic.Delirium.Hugo J, Ganguli M.Dementia and cognitive impairment: epidemiology, diagnosis, and treatment.Clin Geriatr Med. 2014;30(3):421–442. doi:10.1016/j.cger.2014.04.001Inouye SK, Westendorp RG, Saczynski JS.Delirium in elderly people.Lancet. 2014;383(9920):911–922. doi:10.1016/S0140-6736(13)60688-1Banovic S, Zunic LJ, Sinanovic O.Communication Difficulties as a Result of Dementia.Mater Sociomed. 2018;30(3):221–224. doi:10.5455/msm.2018.30.221-224Green S, Reivonen S, Rutter LM, et al.Investigating speech and language impairments in delirium: A preliminary case-control study.PLoS One. 2018;13(11):e0207527. doi:10.1371/journal.pone.0207527Gold CA, Budson AE.Memory loss in Alzheimer’s disease: implications for development of therapeutics.Expert Rev Neurother. 2008;8(12):1879–1891. doi:10.1586/14737175.8.12.1879O’Regan NA, Ryan DJ, Boland E, et al.Attention! A good bedside test for delirium?.J Neurol Neurosurg Psychiatry. 2014;85(10):1122–1131. doi:10.1136/jnnp-2013-307053FDA-approved treatments for Alzheimer’s.Alzheimer’s Association[internet].Grover S, Avasthi A.Clinical Practice Guidelines for Management of Delirium in Elderly.Indian J Psychiatry. 2018;60(Suppl 3):S329–S340. doi:10.4103/0019-5545.224473Flanagan NM, Fick DM.Delirium superimposed on dementia. Assessment and intervention.J Gerontol Nurs. 2010;36(11):19–23.Morandi A, Davis D, Bellelli G, et al.The Diagnosis of Delirium Superimposed on Dementia: An Emerging Challenge.J Am Med Dir Assoc. 2017;18(1):12–18. doi:10.1016/j.jamda.2016.07.014Additional ReadingFlanagan NM, Fick DM. Delirium Superimposed on Dementia: Assessment and Intervention.Journal of Gerontological Nursing. 2010;36(11):19-23.Journal of Gerontology: Medical Sciences. 2007, Vol. 62A, No. 11, 1306–1309. Delirium Superimposed on Dementia Predicts 12-Month Survival in Elderly Patients Discharged From a Postacute Rehabilitation Facility.Lippmann S, Perugula ML. Delirium or dementia? 2016;13(9-10). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5141598/.
12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Duong S, Patel T, Chang F.Dementia: What pharmacists need to know.Can Pharm J (Ott). 2017;150(2):118–129. doi:10.1177/1715163517690745The Mayo Clinic.Delirium.Hugo J, Ganguli M.Dementia and cognitive impairment: epidemiology, diagnosis, and treatment.Clin Geriatr Med. 2014;30(3):421–442. doi:10.1016/j.cger.2014.04.001Inouye SK, Westendorp RG, Saczynski JS.Delirium in elderly people.Lancet. 2014;383(9920):911–922. doi:10.1016/S0140-6736(13)60688-1Banovic S, Zunic LJ, Sinanovic O.Communication Difficulties as a Result of Dementia.Mater Sociomed. 2018;30(3):221–224. doi:10.5455/msm.2018.30.221-224Green S, Reivonen S, Rutter LM, et al.Investigating speech and language impairments in delirium: A preliminary case-control study.PLoS One. 2018;13(11):e0207527. doi:10.1371/journal.pone.0207527Gold CA, Budson AE.Memory loss in Alzheimer’s disease: implications for development of therapeutics.Expert Rev Neurother. 2008;8(12):1879–1891. doi:10.1586/14737175.8.12.1879O’Regan NA, Ryan DJ, Boland E, et al.Attention! A good bedside test for delirium?.J Neurol Neurosurg Psychiatry. 2014;85(10):1122–1131. doi:10.1136/jnnp-2013-307053FDA-approved treatments for Alzheimer’s.Alzheimer’s Association[internet].Grover S, Avasthi A.Clinical Practice Guidelines for Management of Delirium in Elderly.Indian J Psychiatry. 2018;60(Suppl 3):S329–S340. doi:10.4103/0019-5545.224473Flanagan NM, Fick DM.Delirium superimposed on dementia. Assessment and intervention.J Gerontol Nurs. 2010;36(11):19–23.Morandi A, Davis D, Bellelli G, et al.The Diagnosis of Delirium Superimposed on Dementia: An Emerging Challenge.J Am Med Dir Assoc. 2017;18(1):12–18. doi:10.1016/j.jamda.2016.07.014Additional ReadingFlanagan NM, Fick DM. Delirium Superimposed on Dementia: Assessment and Intervention.Journal of Gerontological Nursing. 2010;36(11):19-23.Journal of Gerontology: Medical Sciences. 2007, Vol. 62A, No. 11, 1306–1309. Delirium Superimposed on Dementia Predicts 12-Month Survival in Elderly Patients Discharged From a Postacute Rehabilitation Facility.Lippmann S, Perugula ML. Delirium or dementia? 2016;13(9-10). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5141598/.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Duong S, Patel T, Chang F.Dementia: What pharmacists need to know.Can Pharm J (Ott). 2017;150(2):118–129. doi:10.1177/1715163517690745The Mayo Clinic.Delirium.Hugo J, Ganguli M.Dementia and cognitive impairment: epidemiology, diagnosis, and treatment.Clin Geriatr Med. 2014;30(3):421–442. doi:10.1016/j.cger.2014.04.001Inouye SK, Westendorp RG, Saczynski JS.Delirium in elderly people.Lancet. 2014;383(9920):911–922. doi:10.1016/S0140-6736(13)60688-1Banovic S, Zunic LJ, Sinanovic O.Communication Difficulties as a Result of Dementia.Mater Sociomed. 2018;30(3):221–224. doi:10.5455/msm.2018.30.221-224Green S, Reivonen S, Rutter LM, et al.Investigating speech and language impairments in delirium: A preliminary case-control study.PLoS One. 2018;13(11):e0207527. doi:10.1371/journal.pone.0207527Gold CA, Budson AE.Memory loss in Alzheimer’s disease: implications for development of therapeutics.Expert Rev Neurother. 2008;8(12):1879–1891. doi:10.1586/14737175.8.12.1879O’Regan NA, Ryan DJ, Boland E, et al.Attention! A good bedside test for delirium?.J Neurol Neurosurg Psychiatry. 2014;85(10):1122–1131. doi:10.1136/jnnp-2013-307053FDA-approved treatments for Alzheimer’s.Alzheimer’s Association[internet].Grover S, Avasthi A.Clinical Practice Guidelines for Management of Delirium in Elderly.Indian J Psychiatry. 2018;60(Suppl 3):S329–S340. doi:10.4103/0019-5545.224473Flanagan NM, Fick DM.Delirium superimposed on dementia. Assessment and intervention.J Gerontol Nurs. 2010;36(11):19–23.Morandi A, Davis D, Bellelli G, et al.The Diagnosis of Delirium Superimposed on Dementia: An Emerging Challenge.J Am Med Dir Assoc. 2017;18(1):12–18. doi:10.1016/j.jamda.2016.07.014
Duong S, Patel T, Chang F.Dementia: What pharmacists need to know.Can Pharm J (Ott). 2017;150(2):118–129. doi:10.1177/1715163517690745
The Mayo Clinic.Delirium.
Hugo J, Ganguli M.Dementia and cognitive impairment: epidemiology, diagnosis, and treatment.Clin Geriatr Med. 2014;30(3):421–442. doi:10.1016/j.cger.2014.04.001
Inouye SK, Westendorp RG, Saczynski JS.Delirium in elderly people.Lancet. 2014;383(9920):911–922. doi:10.1016/S0140-6736(13)60688-1
Banovic S, Zunic LJ, Sinanovic O.Communication Difficulties as a Result of Dementia.Mater Sociomed. 2018;30(3):221–224. doi:10.5455/msm.2018.30.221-224
Green S, Reivonen S, Rutter LM, et al.Investigating speech and language impairments in delirium: A preliminary case-control study.PLoS One. 2018;13(11):e0207527. doi:10.1371/journal.pone.0207527
Gold CA, Budson AE.Memory loss in Alzheimer’s disease: implications for development of therapeutics.Expert Rev Neurother. 2008;8(12):1879–1891. doi:10.1586/14737175.8.12.1879
O’Regan NA, Ryan DJ, Boland E, et al.Attention! A good bedside test for delirium?.J Neurol Neurosurg Psychiatry. 2014;85(10):1122–1131. doi:10.1136/jnnp-2013-307053
FDA-approved treatments for Alzheimer’s.Alzheimer’s Association[internet].
Grover S, Avasthi A.Clinical Practice Guidelines for Management of Delirium in Elderly.Indian J Psychiatry. 2018;60(Suppl 3):S329–S340. doi:10.4103/0019-5545.224473
Flanagan NM, Fick DM.Delirium superimposed on dementia. Assessment and intervention.J Gerontol Nurs. 2010;36(11):19–23.
Morandi A, Davis D, Bellelli G, et al.The Diagnosis of Delirium Superimposed on Dementia: An Emerging Challenge.J Am Med Dir Assoc. 2017;18(1):12–18. doi:10.1016/j.jamda.2016.07.014
Flanagan NM, Fick DM. Delirium Superimposed on Dementia: Assessment and Intervention.Journal of Gerontological Nursing. 2010;36(11):19-23.Journal of Gerontology: Medical Sciences. 2007, Vol. 62A, No. 11, 1306–1309. Delirium Superimposed on Dementia Predicts 12-Month Survival in Elderly Patients Discharged From a Postacute Rehabilitation Facility.Lippmann S, Perugula ML. Delirium or dementia? 2016;13(9-10). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5141598/.
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