mental illness

noun

variants or mental disorder or less commonly mental disease

: any of a broad range of medical conditions (such as major depression, schizophrenia, obsessive compulsive disorder, or panic disorder) that are marked primarily by sufficient disorganization of personality, mind, or emotions to impair normal psychological functioning and cause marked distress or disability and that are typically associated with a disruption in normal thinking, feeling, mood, behavior, interpersonal interactions, or daily functioning

mentally ill adjective

Examples of mental illness in a Sentence

Recent Examples on the Web

At the far end of the spectrum are the parents who have severe mental illnesses, from postpartum depression or anxiety to psychosis. —Jennifer Brookland, Detroit Free Press, 19 June 2024

Berman said that, often times, people with mental illness are couch-surfing or cycling through expensive systems of care, such as emergency rooms or treatment facilities. —Raisa Habersham, Miami Herald, 18 June 2024

Aldrich coordinated a spam email campaign against a former work supervisor who is gay, according to recent court filings, and disseminated another person’s racist and antisemitic manifesto that claimed being transgender is a mental illness. —Emily Wax-Thibodeaux, Washington Post, 18 June 2024

But a circuit court judge in Missouri now says the woman, who suffers from mental illness, should have never been incarcerated – and that a now-deceased local police officer was never properly investigated and should have likely instead been charged with the 1980 killing. —Emily Palmer, Peoplemag, 17 June 2024

Word History

First Known Use

1724, in the meaning defined above

Kids Definition

mental illness

noun

variants or mental disorder

: a medical condition that is marked by a mild to severe disturbance in the way a person thinks, feels, or acts and is usually accompanied by distress and problems functioning in daily activities or interacting with others

mentally ill adjective

Medical Definition

mental illness

noun

variants or mental disorder also mental disease

: any of a broad range of medical conditions (such as major depression, schizophrenia, obsessive compulsive disorder, or panic disorder) that are marked primarily by sufficient disorganization of personality, mind, or emotions to impair normal psychological functioning and cause marked distress or disability and that are typically associated with a disruption in normal thinking, feeling, mood, behavior, interpersonal interactions, or daily functioning

Some homeless families are also hindered by substance abuse and mental illness.

—Ellen L. Bassuk, Scientific American

Catatonia is usually an expression of mental disorders like bipolar disorder or schizophrenia, but it could also come from other medical problems, such as a brain tumor.

—Forrest Wickman, The Pittsburgh Post-Gazette

… mental diseases such as schizophrenia and manic depression may either involve more than one gene or may result from a complex mix of genetic predisposition and environmental rotten luck.

—Natalie Angier, The New York Times Book Review

mentally ill adjective

mentally ill patients

Mental health workers … perform a wide variety of therapeutic, supportive, and preventative functions for persons who are mentally ill and developmentally disabled.

—Barbara M. Swanson, Careers in Health Care

Legal Definition

mental illness

noun

mental ill·​ness

1

: mental disease

2

: a mental condition marked primarily by sufficient disorganization of personality, mind, and emotions to seriously impair the normal psychological and often social functioning of the individual

called also mental disorder