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

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Etymology

Origin of mental illness

First recorded in 1960–65

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Example Sentences

See Examples For:

mental illness

Poverty, bad luck and mental illness can also play a role.

From MarketWatch ● Oct. 26, 2026

In a move reeking of desperation, Ramaswamy’s campaign ran a spot featuring Acton’s elderly mother, Donna Arthur, calling her daughter a “liar” and suggesting she suffers from severe mental illness.

From Salon ● Oct. 23, 2026

Walke believes that giving patients clearer information about their brain activity could also help change public attitudes toward mental illness.

From Science Daily ● Oct. 23, 2026

She prefers using diversion programs to handle defendants suffering from mental illness or addiction issues, according to her campaign website, but hasn’t specifically said she’d ban deputy city attorneys from filing any particular case.

From Los Angeles Times ● Oct. 22, 2026

The numbers of incarcerated people with serious mental illness declined dramatically, while public and private mental health facilities emerged to provide care to the mentally distressed.

From "Just Mercy" by Bryan Stevenson

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Related Words

• insanity
• mental disorder

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