mental illness

American  

noun

• mental illnesses
  plural

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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Other Word Forms

Noun Inflected Forms

• mental illnesses
  plural

Etymology

Origin of mental illness

First recorded in 1960–65

Example Sentences

See Examples For:

mental illness

The dotty pumpkins and kaleidoscope rooms of Yayoi Kusama, who has died aged 97, were as vibrant as the artist herself, but her exuberant work was the expression of a long battle with mental illness.

From Barron's ● Aug. 27, 2026

Her defence says she was suffering from severe postpartum mental illness, including psychosis, while prosecutors argue she acted deliberately.

From BBC ● Aug. 19, 2026

Hoetzlein had a history of severe mental illness, the statement said.

From Los Angeles Times ● Aug. 17, 2026

Meta now faces thousands of lawsuits in state and federal courts alleging that it fueled an epidemic of youth mental illness.

From The Wall Street Journal ● Aug. 16, 2026

At Brandeis, he taught classes about social psychology, mental illness and health, group process.

From "Tuesdays with Morrie" by Mitch Albom

Related Words

• insanity
• mental disorder