Psychosis is a symptom or feature of mental illness typically characterized by radical changes in personality, impaired functioning, and a distorted or nonexistent sense of objective reality.
Patients suffering from psychosis have impaired reality testing; that is, they are unable to distinguish personal subjective experience from the reality of the external world. They experience hallucinations
that they believe are real, and may behave and communicate in an inappropriate and incoherent fashion. Psychosis may appear as a symptom of a number of mental disorders, including mood and personality disorders
. It is also the defining feature of schizophrenia
, schizophreniform disorder, schizoaffective disorder
, delusional disorder, and the psychotic disorders (i.e., brief psychotic disorder, shared psychotic disorder, psychotic disorder due to a general medical condition, and substance-induced psychotic disorder).
Causes and symptoms
Psychosis may be caused by the interaction of biological and psychosocial factors depending on the disorder in which it presents; psychosis can also be caused by purely social factors, with no biological component.
Biological factors that are regarded as contributing to the development of psychosis include genetic abnormalities and substance use. With regard to chromosomal abnormalities, studies indicate that 30% of patients diagnosed with a psychotic disorder have a microdeletion at chromosome 22q11. Another group of researchers has identified the gene G72/G30 at chromosome 13q33.2 as a susceptibility gene for child-hood-onset schizophrenia and psychosis not otherwise specified.
With regard to substance abuse, several different research groups reported in 2004 that cannabis (marijuana
) use is a risk factor for the onset of psychosis.
Migration is a social factor that influences people's susceptibility to psychotic disorders. Psychiatrists in Europe have noted the increasing rate of schizophrenia and other psychotic disorders among immigrants to almost all Western European countries. Black immigrants from Africa or the Caribbean appear to be especially vulnerable. The stresses involved in migration include family breakup, the need to adjust to living in large urban areas, and social inequalities in the new country.
Schizophrenia, schizophreniform disorder, and schizoaffective disorder
Psychosis in schizophrenia and perhaps schizophreniform disorder appears to be related to abnormalities in the structure and chemistry of the brain, and appears to have strong genetic links; but its course and severity can be altered by social factors such as stress
or a lack of support within the family. The cause of schizoaffective disorder is less clear cut, but biological factors are also suspected.
The exact cause of delusional disorder has not been conclusively determined, but potential causes include heredity, neurological abnormalities, and changes in brain chemistry. Some studies have indicated that delusions are generated by abnormalities in the limbic system, the portion of the brain on the inner edge of the cerebral cortex that is believed to regulate emotions. Delusional disorder is also more likely to develop in persons who are isolated from others in their society by language difficulties and/or cultural differences.
Brief psychotic disorder
Trauma and stress can cause a short-term psychosis (less than a month's duration) known as brief psychotic disorder. Major life-changing events such as the death
of a family member or a natural disaster have been known to stimulate brief psychotic disorder in patients with no prior history of mental illness.
Psychotic disorder due to a general medical condition
Psychosis may also be triggered by an organic cause, termed a psychotic disorder due to a general medical condition. Organic sources of psychosis include neurological conditions (for example, epilepsy and cerebrovascular disease), metabolic conditions (for example, porphyria), endocrine conditions (for example, hyper- or hypothyroidism
), renal failure, electrolyte imbalance, or autoimmune disorders
Substance-induced psychotic disorder
Psychosis is also a known side effect of the use, abuse
, and withdrawal from certain drugs. So-called recreational drugs, such as hallucinogenics, PCP, amphetamines, cocaine
, marijuana, and alcohol, may cause a psychotic reaction during use or withdrawal. Certain prescription medications such as steroids, anticonvulsants, chemotherapeutic agents, and antiparkinsonian medications may also induce psychotic symptoms. Toxic substances such as carbon monoxide have also been reported to cause substance-induced psychotic disorder.
Shared psychotic disorder
Shared psychotic disorder, also known as folie à deux or psychosis by association, is a relatively rare delusional disorder involving two (or more) people with close emotional ties. In the West, shared psychosis most commonly develops between two sisters or between husband and wife, while in Japan the most common form involves a parent and a son or daughter. Shared psychosis occasionally involves an entire nuclear family.
Psychosis is characterized by the following symptoms:
- Delusions. Those delusions that occur in schizophrenia and its related forms are typically bizarre (i.e., they could not occur in real life). Delusions occurring in delusional disorder are more plausible, but still patently untrue. In some cases, delusions may be accompanied by feelings of paranoia.
- Hallucinations. Psychotic patients see, hear, smell, taste, or feel things that aren't there. Schizophrenic hallucinations are typically auditory or, less commonly, visual; but psychotic hallucinations can involve any of the five senses.
- Disorganized speech. Psychotic patients, especially those with schizophrenia, often ramble on in incoherent, nonsensical speech patterns.
- Disorganized or catatonic behavior. The catatonic patient reacts inappropriately to his/her environment by either remaining rigid and immobile or by engaging in excessive motor activity. Disorganized behavior is behavior or activity that is inappropriate for the situation, or unpredictable.
Patients with psychotic symptoms should undergo a thorough physical examination
and history to rule out such possible organic causes as seizures, delirium
, or alcohol withdrawal, and such other psychiatric conditions as dissociation or panic attacks. If a psychiatric cause such as schizophrenia is suspected, a mental health professional will typically conduct an interview with the patient and administer one of several clinical inventories, or tests, to evaluate mental status. This assessment takes place in either an out-patient or hospital setting.
Psychotic symptoms and behaviors are considered psychiatric emergencies, and persons showing signs of psychosis are frequently taken by family, friends, or the police to a hospital emergency room. A person diagnosed as psychotic can be legally hospitalized against his or her will, particularly if he or she is violent, threatening to commit suicide
, or threatening to harm another person. A psychotic person may also be hospitalized if he or she has become malnourished or ill as a result of failure to feed, dress appropriately for the climate, or otherwise take care of him- or herself.
Psychosis that is symptomatic of schizophrenia or another psychiatric disorder should be treated by a psychologist and/or psychiatrist. An appropriate course of medication and/or psychosocial therapy is employed to treat the underlying primary disorder. If the patient is considered to be at risk for harming himself or others, inpatient treatment is usually recommended.
Treatment of shared psychotic disorder involves separating the affected persons from one another as well as using antipsychotic medications and psychotherapy.
Antipsychotic medication such as thioridazine (Mellaril), haloperidol (Haldol), chlorpromazine (Thorazine), clozapine (Clozaril), sertindole (Serlect), olanzapine (Zyprexa), or risperidone (Risperdal) is usually prescribed to bring psychotic symptoms under control and into remission. Possible side effects of antipsychotics include dry mouth
, drowsiness, muscle stiffness, and tardive dyskinesia
(involuntary movements of the body). Agranulocytosis, a potentially serious but reversible health condition in which the white blood cells that fight infection in the body are destroyed, is a possible side effect of clozapine. Patients treated with this drug should undergo weekly blood tests to monitor white blood cell counts for the first six months, then every two weeks.
After an acute psychotic episode has subsided, antipsychotic drug maintenance treatment is typically employed and psychosocial therapy and living and vocational skills training may be attempted.
Prognosis for brief psychotic disorder is quite good; for schizophrenia, less so. Generally, the longer and more severe a psychotic episode, the poorer the prognosis is for the patient. Early diagnosis and treatment are critical to improving outcomes for the patient across all psychotic disorders.
Approximately 10% of America's permanently disabled population is comprised of schizophrenic individuals. The mortality rate of schizophrenic individuals is also high—approximately 10% of schizophrenics commit suicide, and 20% attempt it. However, early diagnosis and long-term follow up care can improve the outlook for these patients considerably. Roughly 60% of patients with schizophrenia will show substantial improvement with appropriate treatment.
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Brief psychotic disorder
— An acute, short-term episode of psychosis lasting no longer than one month. This disorder may occur in response to a stressful event.
— An acute but temporary disturbance of consciousness marked by confusion, difficulty paying attention, delusions, hallucinations, or restlessness. Delirium may be caused by drug intoxication, high fever related to infection, head trauma, brain tumors, kidney or liver failure, or various metabolic disturbances.
— Individuals with delusional disorder suffer from long-term, complex delusions that fall into one of six categories: persecutory, grandiose, jealousy, erotomanic, somatic, or mixed.
— An unshakable belief in something untrue which cannot be explained by religious or cultural factors. These irrational beliefs defy normal reasoning and remain firm even when overwhelming proof is presented to refute them.
— False or distorted sensory experiences that appear to be real perceptions to the person experiencing them.
— An unfounded or exaggerated distrust of others, sometimes reaching delusional proportions.
— A disease of the metabolism characterized by skin lesions, urine problems, neurologic disorders, and/or abdominal pain.
— A debilitating mental illness characterized by delusions, hallucinations, disorganized speech and behavior, and inappropriate or flattened affect (a lack of emotions) that seriously hampers the afflicted individual's social and occupational functioning. Approximately 2 million Americans suffer from schizophrenia.
Shared psychotic disorder
— Also known as folie à deux
, shared psychotic disorder is an uncommon disorder in which the same delusion is shared by two or more individuals.
— Involuntary movements of the face and/or body which are a side effect of the long-term use of some older antipsychotic (neuroleptic) drugs. Tardive dyskinesia affects 15-20% of patients on long-term neuroleptic treatment.
American Psychiatric Association. 1400 K Street NW, Washington DC 20005. (888) 357-7924. http://www.psych.org.
American Psychological Association (APA). 750 First St. NE, Washington, DC 20002-4242. (202) 336-5700. http://www.apa.org.
National Alliance for the Mentally Ill (NAMI). Colonial Place Three, 2107 Wilson Blvd., Ste. 300, Arlington, VA 22201-3042. (800) 950-6264. http://www.nami.org.
National Institute of Mental Health (NIMH). 6001 Executive Boulevard, Room 8184, MSC 9663, Bethesda, MD 20892-9663. (301) 443-4513. http://www.nimh.nih.gov.
The Schizophrenia Page. http://www.schizophrenia.com.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.