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
Universal background checks, modest waiting periods, restricting gun ownership for those with some mental illnesses, and those with a history of violent crime are examples of good gun control that most people support.
—
Rafael Perez, Oc Register, 1 Aug. 2025
Claiborne's defense argued for not guilty by reason of insanity due to a history of mental illness, but the jury rejected this argument.
—Quinlan Bentley, The Enquirer, 31 July 2025
The Midtown Manhattan shooter speculated that the condition was a cause of his mental illness.
—Yasmin Tayag, The Atlantic, 29 July 2025
Tenants of the building include the NFL, Rudin Management, KPMG and Blackstone.
Officials familiar with the investigation told NBC News that the suspect left a note at the scene voicing anger that his mental illness may be linked to his having played football.
—Erik Ortiz, NBC news, 29 July 2025
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Rafael Perez, Oc Register, 1 Aug. 2025
Claiborne's defense argued for not guilty by reason of insanity due to a history of mental illness, but the jury rejected this argument.
—Quinlan Bentley, The Enquirer, 31 July 2025
The Midtown Manhattan shooter speculated that the condition was a cause of his mental illness.
—Yasmin Tayag, The Atlantic, 29 July 2025
Tenants of the building include the NFL, Rudin Management, KPMG and Blackstone.
Officials familiar with the investigation told NBC News that the suspect left a note at the scene voicing anger that his mental illness may be linked to his having played football.
—Erik Ortiz, NBC news, 29 July 2025
See All Example Sentences for mental illness
Cite this Entry
“Mental illness.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mental%20illness. Accessed 6 Aug. 2025.
Copy CitationMedical 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
Ellen L. Bassuk, Scientific AmericanCatatonia 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
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
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
Barbara M. Swanson, Careers in Health Care
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