dementia

noun

de·​men·​tia di-ˈmen(t)-shə 

-shē-ə

1

: a usually progressive condition (such as Alzheimer's disease) marked by the development of multiple cognitive deficits (such as memory impairment, aphasia, and the inability to plan and initiate complex behavior)

… dementia is diagnosed only when both memory and another cognitive function are each affected severely enough to interfere with a person's ability to carry out routine daily activities.

—The Journal of the American Medical Association

2

: madness, insanity

a fanaticism bordering on dementia

demential

di-ˈmen(t)-shəl 

-shē-əl

adjective

Synonyms

• aberration
• derangement
• insanity
• lunacy
• madness
• mania
• rage [archaic]

Examples of dementia in a Sentence

This patient suffers from dementia.

a new study on age-related dementias

Recent Examples on the Web

Green tea may also protect against the following chronic health conditions: Alzheimer’s disease: Drinking green tea regularly may reduce the risk of Alzheimer’s disease and dementia. —Carrie Madormo, Rn, Mph, Verywell Health, 25 Oct. 2024

Investigators also found that Alzheimer’s disease was more accurately detected in individuals who had already progressed to dementia, compared to those with mild cognitive decline who were less likely to have this diagnosis regardless. —William A. Haseltine, Forbes, 25 Oct. 2024

Sara Schmidt was 35 years old when her mother, Brenda, who had early onset Parkinson's and dementia, took a bad fall in 2021. —Jessica Guynn, USA TODAY, 25 Oct. 2024

While getting Type 2 diabetes under control may already lower the risk for Alzheimer's disease, there may be additional dementia risk reduction for semaglutide, according to Rong Xu, lead researcher and professor of biomedical informatics at Case Western. —Mary Kekatos, ABC News, 24 Oct. 2024

Word History

Etymology

borrowed from Latin dēmentia "derangement, insanity, folly," noun derivative of Latin dēment-, dēmens "out of one's mind, frenzied, insane," from dē- de- + -ment, -mens, adjective derivative of ment-, mens "power of reason, mental balance, mind" — more at mind entry 1

First Known Use

1806, in the meaning defined at sense 1

Phrases Containing dementia

• dementia praecox
• dementia pugilistica
• senile dementia

Kids Definition

dementia

noun

de·​men·​tia di-ˈmen-chə 

1

: a condition of the brain that is marked especially by a deterioration in the ability to think, reason, or remember

2

: a condition of deteriorating mental functioning

Medical Definition

dementia

noun

de·​men·​tia di-ˈmen-chə 

: a usually progressive condition (as Alzheimer's disease) marked by the development of multiple cognitive deficits (as memory impairment, aphasia, and inability to plan and initiate complex behavior)

demential

-chəl 

adjective