noun \sī-ˈkō-səs\

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

plural psy·cho·ses\-ˌsēz\

Full Definition of PSYCHOSIS

:  fundamental derangement of the mind (as in schizophrenia) characterized by defective or lost contact with reality especially as evidenced by delusions, hallucinations, and disorganized speech and behavior

Examples of PSYCHOSIS

  1. The patient suffers from some kind of psychosis.


New Latin
First Known Use: 1847

Other Psychology Terms

fetish, hypochondria, intelligence, mania, narcissism, neurosis, pathological, schadenfreude, subliminal


noun \sī-ˈkō-səs\   (Medical Dictionary)
plural psy·cho·ses \-ˌsēz\

Medical Definition of PSYCHOSIS

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


noun    (Concise Encyclopedia)

Any of several serious mental illnesses characterized by defects in judgment and other cognitive processes and by loss of contact with reality. Psychoses can be divided into two major types: functional and organic. Functional psychoses include schizophrenia and affective disorders (also called mood disorders), such as major depressive disorder and bipolar disorder. Organic psychoses arise secondary to a preexisting medical condition such as Alzheimer disease and share important features with functional psychoses. Certain medications, including narcotics (used to treat pain) and levodopa (used to treat Parkinson disease), can cause symptoms of psychoses. The major symptoms, aside from delusions and hallucinations, are disorganized speech and behaviour, lack of emotional expression, and apathy. Treatment usually consists of medication and psychotherapy; severe cases may require permanent hospitalization. Compare neurosis.


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