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

Financial independence isn’t always possible for everyone, especially when faced with challenges including physical and mental illness.

From MarketWatch ● Jun. 19, 2026

From one angle or another, I’ve been writing about the intersection of homelessness, mental illness and addiction for a couple of decades, and I still have a lot to learn.

From Los Angeles Times ● Jun. 6, 2026

The result can be heard in songs like the hard-driving “Is It Real?” in which Hollywell roars about mental illness and divine intervention, while Santos coats it all in steel honey.

From Salon ● Jun. 5, 2026

Court psychiatrist Peter Hoffmann said Beran A showed no signs of mental illness, adding that there was "no psychiatric explanation" for his radicalisation.

From BBC ● May 28, 2026

At this time there is little understanding of mental illness.

From "Vincent and Theo: The Van Gogh Brothers" by Deborah Heiligman

Related Words

• insanity
• mental disorder