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

Homelessness can cause mental illness, and mental illness can cause addiction, and vice versa.

From Los Angeles Times • Jun. 6, 2026

Likewise, at a time when homosexuality was charged as a crime and classified as a mental illness, plenty of men who loved men married women, and plenty of women who loved women married men.

From Salon • Jun. 3, 2026

Its hero, Wilbur Budd, is grappling not with mental illness, as Nora was, but with grief and missed opportunities.

From The Wall Street Journal • May 25, 2026

Maddock and Smucny have long studied how brain chemistry is connected to mental illness using proton magnetic resonance spectroscopy, also known as 1H-MRS.

From Science Daily • May 16, 2026

We didn’t even have the language to talk about mental illness in my culture.

From "How Dare the Sun Rise" by Sandra Uwiringiyimana

Related Words

• insanity
• mental disorder