psy·​cho·​sis | \ sī-ˈkō-səs How to pronounce psychosis (audio) \
plural psychoses\ sī-​ˈkō-​ˌsēz How to pronounce psychoses (audio) \

Definition of psychosis

: a serious mental illness (such as schizophrenia) characterized by defective or lost contact with reality often with hallucinations or delusions

Examples of psychosis in a Sentence

The patient suffers from some kind of psychosis.
Recent Examples on the Web After his hospitalization in 2016 for psychosis and bipolar disorder, West left the hospital starving for something that would give him order and purpose. John Hirschauer, National Review, "Kanye West’s Reactionary Turn Isn’t Just an Act," 4 Nov. 2019 Meth can keep individuals awake for days on end, causing psychosis and even organ failure. Parker Schorr, Milwaukee Journal Sentinel, "While millions are spent to fight the opioid epidemic, a meth crisis quietly grows in Wisconsin," 17 Oct. 2019 Some mass shooters have a history of schizophrenia or psychosis, but many do not., "Are video games or mental illness causing America’s mass shootings? No, research shows.," 5 Aug. 2019 Experts testified on several days spread out over two weeks, agreeing that Guerrero is severely mentally ill, with psychosis and long-term schizophrenia. Pauline Repard, San Diego Union-Tribune, "Suspect in deadly attacks on homeless found competent for trial," 5 June 2019 Myth #2: Everyone who takes antipsychotics has schizophrenia or psychosis. Kasandra Brabaw, SELF, "7 Myths You Might Believe About Antipsychotic Medications," 7 Dec. 2018 Even the film’s detractors -- and there are many -- had to admit that Phoenix’s go-for-broke portrait of psychosis is an acting tour-de-force. Brent Lang,, "10 biggest winners and losers at the Toronto Film Festival," 12 Sep. 2019 And at high doses, with high-strength strains or long-term use, there is a risk of psychosis. The Economist, "A global revolution in attitudes towards cannabis is under way," 29 Aug. 2019 The oddity is that Gottlieb and his circle saw acid as causing breakdowns and psychosis—and, indeed, their stealthy experiments produced such symptoms, even in the relatively benign premises of the Village and North Beach. Adam Gopnik, The New Yorker, "Are Spies More Trouble Than They’re Worth?," 26 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'psychosis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of psychosis

1847, in the meaning defined above

History and Etymology for psychosis

New Latin

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Time Traveler for psychosis

Time Traveler

The first known use of psychosis was in 1847

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Statistics for psychosis

Last Updated

24 Nov 2019

Cite this Entry

“Psychosis.” The Dictionary, Merriam-Webster Inc., Accessed 10 December 2019.

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More Definitions for psychosis


How to pronounce psychosis (audio)

English Language Learners Definition of psychosis

: a very serious mental illness that makes you behave strangely or believe things that are not true


psy·​cho·​sis | \ sī-ˈkō-səs How to pronounce psychosis (audio) \
plural psychoses\ -​ˌsēz How to pronounce psychoses (audio) \

Medical Definition of psychosis

: a serious mental illness (as schizophrenia) characterized by defective or lost contact with reality often with hallucinations or delusions

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Comments on psychosis

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


to state or do over again or repeatedly

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