psychosis

/suy koh"sis/, n., pl. psychoses /-seez/.

1. a mental disorder characterized by symptoms, such as delusions or hallucinations, that indicate impaired contact with reality.

2. any severe form of mental disorder, as schizophrenia or paranoia.

[1840-50; < LGk psýchosis animation, principle of life. See PSYCH-, -OSIS]

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Serious mental derangement characterized by defective or lost contact with reality.

The primary psychoses are schizophrenia and the delusional disorders (e.g., megalomania), but extreme cases of depression and bipolar disorder, substance-induced delirium, and certain varieties of dementia are also understood to share important features with the psychoses. The major symptoms, aside from delusions and hallucinations, are disorganized speech and behaviour and, often, mood disturbances. Treatment usually consists of medication and counseling in an institutional setting. Compare neurosis.

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▪ psychology

Introduction

plural  Psychoses,  

      any of several major mental illnesses that can cause delusions, hallucinations, serious defects in judgment and insight, defects in the thinking process, and the inability to objectively evaluate reality.

      It is difficult to clearly demarcate psychoses from the class of less severe mental disorders known as psychoneuroses (commonly called neuroses) because a neurosis (psychoneurosis) may be so severe, disabling, or disorganizing in its effects that it actually constitutes a psychosis. But, in general, patients suffering from the recognized psychotic illnesses exhibit a disturbed sense of reality and a disorganization of personality that sets them apart from neurotics. Such patients also frequently believe that nothing is wrong with them, despite the palpable evidence to the contrary as evinced by their confused or bizarre behaviour. Psychotics may require hospitalization because they cannot take care of themselves or because they may constitute a danger to themselves or to others.

      Psychoses may be divided into two categories—organic and functional. Organic psychoses are those caused by a known physical abnormality, which in most cases is some organic disease of the brain. All other psychoses are called functional ones.

Functional psychoses.

       schizophrenia (q.v.) is the most common and the most potentially severe and disabling of the psychoses. Schizophrenia is characterized by a withdrawal from reality, delusions and hallucinations, a loosening and incoherence of a person's thought processes, and deficiencies in feeling appropriate or normal emotions. Other symptoms may include apathy, reduced drive and initiative, inability to feel any emotion whatsoever, and a preoccupation with silly or bizarre fantasies. The symptoms of schizophrenia typically first manifest themselves during the teen years or early adult life. The course of the disease is variable: some schizophrenics suffer one acute episode and then permanently recover; others suffer from repeated episodes with periods of remission in between; and still others become chronically psychotic and must be permanently hospitalized.

      Despite prolonged research, the cause or causes of schizophrenia remain largely unknown. It is clear, however, that there is a genetic predisposition to the disease that is inherited. Thus the children of schizophrenic parents stand a greatly increased chance of themselves becoming schizophrenic. The symptoms of schizophrenia can be treated, but not cured, with such antipsychotic drugs as chlorpromazine and other phenothiazine drugs and by haloperidol. psychotherapy may be useful in alleviating distress and helping the patient to cope with the effects of his illness.

      The affective psychoses, which are also known as major affective disorders (affective disorder), consist of states of extreme and prolonged depression, extreme mania, or alternating cycles of both of these mood abnormalities. Depression is a sad, hopeless, pessimistic feeling that can cause listlessness; loss of pleasure in one's surroundings, loved ones, and activities; fatigue; slowness of thought and action; insomnia; and reduced appetite. mania is a state of undue and prolonged excitement that is evinced by accelerated, loud, and voluble speech; heightened enthusiasm, confidence, and optimism; rapid and disconnected ideas and associations; rapid or continuous motor activity; impulsive, gregarious, and overbearing behaviour; heightened irritability; and a reduced need for sleep. When depression and mania alternate cyclically or otherwise appear at different times in the same patient, the person is termed to be suffering from a manic-depressive psychosis (bipolar disorder). Manic-depressive patients also frequently suffer from delusions, hallucinations, or other overtly psychotic symptoms. Manic depression often first manifests itself around age 30, and the disease is a long-lasting one. Many such patients can be treated by long-term maintenance on lithium carbonate (lithium), which reduces and prevents the attacks of mania and depression.

      Depression alone can be psychotic if it is severe and disabling enough, and particularly if it is accompanied by delusions, hallucinations, or paranoia. Depression can be effectively treated by a variety of antidepressant drugs, including the tricyclic antidepressants and the monoamine oxidase inhibitors. Electroconvulsive (shock) therapy is useful in some cases, and psychotherapy and behavioral therapy may also be effective. Mania and many cases of depression are believed to be caused by deficiencies or excesses of certain neurotransmitters (neurotransmitter) in the brain. (Neurotransmitters are chemicals that play key roles in the transmission of nerve impulses.)

       paranoia is a special syndrome that can be a feature of schizophrenia (paranoid schizophrenia) and manic-depressive psychosis or can exist by itself. A person suffering from paranoia thinks or believes that other people are plotting or trying to harm, harass, or persecute him in some way. The paranoiac exaggerates trivial incidents in everyday life into menacing or threatening situations and cannot rid himself of his suspicions and apprehensions. Paranoid syndromes can sometimes be treated or alleviated by antipsychotic drugs.

      The functional psychoses are difficult to treat, and drug treatments are the most common and successful approach. Psychoanalysis and other psychotherapies, which are based on developing a patient's insight into his presumed underlying emotional conflicts, are difficult to apply to psychotic patients.

Organic psychoses.

       dementia is the gradual and progressive loss of such intellectual abilities as remembering, thinking, paying attention, and perceiving; it is often a chronic condition. delirium is a clouded, confused state of consciousness and is usually only a temporary condition. Dementia is the principal syndrome in the most common and widespread organic psychosis, Alzheimer's disease. An elderly person with this disease experiences chronic confusion and loss of memory and may experience paranoia or other personality changes. The memory loss becomes more and more far-reaching, and the patient gradually becomes lethargic, inactive, and then dies. Disturbances in the blood supply to the brain caused by cerebral arteriosclerosis (hardening of the arteries) produce symptoms similar to those of Alzheimer's disease.

      Chronic alcoholics often exhibit psychotic symptoms. Alcohol-induced brain damage can result in memory defects and a major decline in intellectual abilities and social skills. Poisoning, head injuries, syphilis, brain tumours, and neurologic abnormalities such as epilepsy can produce a variety of symptoms resembling the psychoses.

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