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

It is also a powerful reminder of the ordeal of serious mental illness and the ever-pressing need to find better drugs to treat it.

From The Wall Street Journal ● Jul. 28, 2026

His mother and lawyers have been quoted as saying that he suffered from mental illness and injury, possibly from his time as an athlete.

From BBC ● Jul. 27, 2026

"We already knew psilocybin could be helpful for treating mental illness," Carhart-Harris said.

From Science Daily ● Jul. 22, 2026

But family alone can’t seem to do much to mitigate, let alone cure, mental illness or the impact of childhood trauma.

From Los Angeles Times ● Jul. 8, 2026

Elizebeth and William may have suspected as much, since two of his brothers also developed severe mental illness.

From "The Woman All Spies Fear" by Amy Butler Greenfield

Related Words

• insanity
• mental disorder