dementia

American  

[dih-men-shuh, -shee-uh] / dɪˈmɛn ʃə, -ʃi ə /

noun

• dementias
  plural

1. a condition characterized by progressive, persistent, severe impairment of intellectual capacity, including memory loss, confusion, and emotional instability, resulting from the loss of or damage to neurons in the brain.

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dementia British  

/ dɪˈmɛnʃə, -ʃɪə /

noun

1. a state of serious emotional and mental deterioration, of organic or functional origin

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dementia Scientific  

/ dĭ-mĕn′shə /

1. Deterioration of intellectual faculties, such as memory, concentration, and judgment, sometimes accompanied by emotional disturbance and personality changes. Dementia is caused by organic damage to the brain (as in Alzheimer's disease), head trauma, metabolic disorders, or the presence of a tumor.

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Other Word Forms

Derived Forms

• demential
  adjective

Inflected Forms

Nouns

• dementias
  plural

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Etymology

Origin of dementia

First recorded in 1800–10; from Latin dēmentia “madness,” equivalent to dēment- “out of one's mind” ( see dement) + -ia noun suffix

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Compare meaning

How does dementia compare to similar and commonly confused words? Explore the most common comparisons:

• dementia vs. senility

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Explanation

If your grandfather suffers from dementia, he has a brain disorder that's causing him to gradually lose his memory and become disoriented and confused. Although dementia is most common in elderly people, it's not a normal part of growing older but a syndrome caused by brain disease or injury. Dementia gets its name from the Latin words de, or "without," and mens, or "mind," which join together to mean "madness," although in English, dementia is not the same thing as madness. One example of an illness that causes dementia is Alzheimer's disease.

Example Sentences

See Examples For:

dementia dementias

NPH is one of the few causes of dementia that can be controlled or reversed with surgical treatment, usually involving the placement of a shunt.

From Los Angeles Times ● Oct. 16, 2026

Stanford University researchers trained an AI model, which from a single night’s sleep, can flag a person’s risk for roughly 130 diseases, including heart attack, stroke, kidney failure and dementia, years before diagnosis.

From MarketWatch ● Oct. 13, 2026

She also said it had helped prevent serious incidents, including falls on a dementia ward.

From BBC ● Oct. 6, 2026

Alzheimer's disease and other forms of dementia came fifth in 2023, killing 2.1 million people.

From Barron's ● Oct. 2, 2026

“I’m the one who has to deal with Dad all year. I’m the one who runs over when he wants help. I’m the one who deals with his dementia and his grief.”

From "We Were Liars" by E. Lockhart

One of the most important possibilities raised by the findings is that ImP itself could become a target for preventing or slowing Alzheimer's disease and related dementias.

From Science Daily ● Oct. 3, 2026

Researchers believe programs that address several risk factors at once may offer greater benefits because Alzheimer's disease and other dementias are affected by multiple aspects of health and lifestyle.

From Science Daily ● Sep. 6, 2026

As the population ages, more people are being diagnosed with Alzheimer’s disease and other dementias.

From The Wall Street Journal ● Aug. 27, 2026

While most Americans believe lifestyle behaviors are very important for brain health, fewer than half strongly link these behaviors with reducing the risk of Alzheimer’s or other dementias, the group said.

From MarketWatch ● Jul. 15, 2026

In benign stupor purely mental stimuli may change the whole clinical picture abruptly and with this produce a change in the intellectual functioning such as we never see in organic dementias or clouded states.

From Benign Stupors A Study of a New Manic-Depressive Reaction Type by John T. (John Thompson) MacCurdy

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Related Words

• brain damage
• mental disorder

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