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

Many wished for strength to combat physical or mental illness.

From Los Angeles Times • Jun. 10, 2026

The just-quirky-girls-at-a-country-club mood does eventually turn darker, but the musical, like some other works of art about mental illness, often falls into the trap of romanticizing it.

From The Wall Street Journal • Jun. 5, 2026

By and large, experts point to systematic failures that leave Americans more vulnerable to mental illness and without access to drug-free interventions, which cost both time and money.

From Salon • May 18, 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

Well, it also took some degree of mental illness, too, but I was suddenly happy for her.

From "The Absolutely True Diary of a Part-Time Indian" by Sherman Alexie

Related Words

• insanity
• mental disorder