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

"This legislation strengthens safeguards and restores clear limits on eligibility to protect vulnerable Albertans facing mental illness or living with disabilities," she said.

From BBC • Mar. 18, 2026

The Metropolitan State Hospital opened in Norwalk in 1916, a self-contained facility complete with its own farm that treated people with mental illness.

From Los Angeles Times • Mar. 6, 2026

Burke told the court that social-media addiction isn’t listed in the Diagnostic and Statistical Manual of Mental Disorders, typically used by clinicians to diagnose mental illness.

From The Wall Street Journal • Feb. 26, 2026

Claire Brosseau rails against the idea that people with mental illness are incapable of making informed decisions.

From Barron's • Feb. 25, 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