mental illness

noun
variants: or

mental disorder

or less commonly

mental disease

Definition of mental illness

  1. :  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

First Known Use of mental illness

1724


Medical Dictionary

mental illness

noun
variants: or

mental disorder

also

mental disease

Medical Definition of mental illness

  1. :  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, December 1991 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, 31 May 2012 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, 12 Aug. 1990

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, 1989

Law Dictionary

mental illness

noun mental ill·ness

Legal Definition of mental illness

  1. 1 :  mental disease

  2. 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


Learn More about mental illness


Seen and Heard

What made you want to look up mental illness? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

to plunder or ravage

Get Word of the Day daily email!

Test Your Vocabulary

Time Traveler Quiz: Which Word Came First?

  • time-traveler-quiz-which-word-came-first
  • Which came first?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!