mental illness

American  

noun

1. any of the various forms of psychosis or severe neurosis.

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mental illness British  

noun

1. any of various disorders in which a person's thoughts, emotions, or behaviour are so abnormal as to cause suffering to himself, herself, or other people

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mental illness Scientific  

/ mĕn′tl /

1. Any of various psychiatric disorders or diseases, usually characterized by impairment of thought, mood, or behavior.

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Etymology

Origin of mental illness

First recorded in 1960–65

Example Sentences

“If we have over 60% of the population living outdoors struggling with extreme mental illness or extreme drug addiction, giving them a key is not the solution,” she said.

From Los Angeles Times • May 1, 2026

On Thursday, Seedat said that comment was made in a "frank conversation" with Calocane about his mental illness.

From BBC • Apr. 23, 2026

President Donald Trump signs a directive to accelerate FDA review of psychedelic drugs for serious mental illness.

From Barron's • Apr. 20, 2026

Carruthers’ case is a perfect storm of capital punishment’s familiar failures: paid informants, information withheld from the jury, untested physical evidence, and the defendant’s mental illness.

From Slate • Apr. 20, 2026

President Reagan's attacker, like Charles Guiteau, had a history of mental illness.

From "Ambushed!" by Gail Jarrow

Related Words

• insanity
• mental disorder