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

Historically this has applied to prisoners with dementia or psychosis, but experts have said there is a chance that Pike has suffered brain damage.

From BBC ● Oct. 7, 2026

Meanwhile dementia deaths have tripled and anxiety- and depression-related health loss has risen sharply since the Covid-19 pandemic.

From Barron's ● Oct. 2, 2026

I was uncertain if this referred to Bud or to a literal blue jay, or if, perhaps, we were heading into the territory of senile dementia.

From "The Secret History" by Donna Tartt

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

In turn, targeted therapies will either prevent Alzheimer’s in the first place or convert it and other progressive dementias into chronically manageable or even curable conditions.

From The Wall Street Journal ● Jun. 20, 2026

Medicare and Medicaid are expected to cover $263 billion, or 64%, of the total healthcare and long-term-care payments for people living with Alzheimer’s or other dementias.

From MarketWatch ● May 19, 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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