Schizophrenia

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A term coined by Bleuler, synonymous with and replacing dementia praecox; a common type of psychosis, characterized by abnormalities in perception, content of thought, and thought processes (hallucinations and delusions) and by extensive withdrawal of interest from other people and the outside world, with excessive focusing on one's own mental life; now considered a group or spectrum of disorders rather than a single entity, with distinction sometimes made between process s. and reactive s.. The “split” personality of s., in which individual psychic components or functions split off and become autonomous, is popularly but erroneously identified with multiple personality, in which 2 or more relatively complete personalities dominate by turns the psychic life of an individual. [schizo- + G. phren, mind] S. is the most prevalent psychosis, affecting some 2 million Americans. The annual cost of the disease to the U.S. economy is estimated at $65 billion, of which $46 billion reflects lost productivity of patients and their caregivers. The lifetime incidence risk is about 1%. Onset is typically gradual, without an obvious precipitating cause. Early symptoms include shortened attention span, memory deficits, and diminished ability to make decisions. Most patients become ill before age 40. Psychotic symptoms persist for months or years, and there is a lifelong risk of relapse. Cognitive malfunctions are typically accompanied by reduced energy level, flat or depressed affect, anhedonia, and abulia. Virtually all patients display impoverished thought content, social withdrawal, and impairment of occupational functioning, and even with intensive psychotherapy and drug treatment about 25% require custodial or institutional care. Although some persons with s. become assassins or mass murderers, the vast majority pose no threat to society; about 10% commit suicide. Neurophysiologic studies have shown generalized limbic lobe and prefrontal cortical abnormalities, abnormal smallness of the thalamus, and changes in signal intensity in adjacent white matter. Brain imaging inconsistently demonstrates structural or physiologic abnormalities in the prefrontal cortex, cingulate cortex, temporal cortex, and hippocampal formation. The amelioration or exacerbation of s. by certain pharmacologic agents seems to indicate that it represents a malfunction of neuronal systems using dopamine, serotonin, glutamate, and γ-aminobutyric acid (GABA) as transmitters or modulators. Genetic studies suggest that susceptibility to s. is inherited as a complex of variations affecting several genes. According to the neurodevelopmental hypothesis, a brain lesion is present or acquired early in life but does not fully manifest itself until late adolescence or early adulthood, when it triggers abnormalities of neuronal proliferation, axonal outgrowth, cell migration, cell survival, synaptic regression, or myelination. Psychotherapy and behavioral therapy are inconsistently effective in the treatment of s.. Neuroleptic drugs shorten episodes of acute psychosis, limit the need for institutional care, and reduce the risk of relapse, but their long-term use is associated with serious side effect s, particularly tardive dyskinesia. Newer agents such as clozapine, olanzipine, quetiapine, and risperidone are more effective in improving cognitive function and less likely to induce extrapyramidal side effect s. Persons with s. frequently stop taking their medicine, and it is estimated that at any given time only one-half of them are receiving medical treatment or supervision.

- acute s. a disorder in which the symptoms of s. occur abruptly; they may subside or become chronic over time. SYN: acute schizophrenic episode.

- ambulatory s. a milder form of s. in which the patient is capable of maintaining himself or herself in society and need not be hospitalized.

- catatonic s. s. characterized by marked disturbance, which may involve stupor, negativism, rigidity, excitement, or posturing; sometimes there is rapid alternation between the extremes of excitement and stupor. Associated features include stereotypic behavior, mannerisms, and waxy flexibility; mutism is particularly common.

- childhood s. SYN: infantile autism.

- disorganized s. a severe form of s. characterized by the predominance of incoherence, blunted, inappropriate or silly affect, and the absence of systematized delusions. SYN: hebephrenic s..

- hebephrenic s. SYN: disorganized s..

- latent s. a preexisting susceptibility for developing overt s. under strong emotional stress.

- paranoid s. s. characterized predominantly by delusions of persecution and megalomania.

- process s. an obsolete term for those forms of severe schizophrenic disorders in which chronic and progressive biologic conditions in the brain are considered to be the primary cause and in which prognosis is poor as well, with insidious onset at a young age, as contrasted with reactive s..

- pseudoneurotic s. s. in which the underlying psychotic process is masked by complaints ordinarily regarded as neurotic.

- reactive s. those forms of severe schizophrenic disorders which are distinguished from process s. by their more acute onset, greater relation to environmental stress, and better prognosis.

- residual s. blunted or inappropriate affect, social withdrawal, eccentric behavior, or loose associations, but without prominent psychotic symptoms, as the remains of former psychotic symptoms of s..

- simple s. s. characterized by withdrawal, apathy, indifference, and impoverishment of human relationships without overt psychotic features.