In 1896, the German psychiatrist Emil Kraepelin grouped what were previously considered unrelated mental diseases under the term
Schizophrenic disorders generally begin in the late teenage years or early adulthood and tend to occur in withdrawn, seclusive individuals. The lifetime prevalence worldwide has been estimated to be just under 1%, and the disorder affects 1.5 to 2 million people in the United States alone. Symptoms include disturbances of thought, both in form and content (see delusion), and disturbances of perception, most commonly appearing as visual or aural hallucinations.
There are five major types of schizophrenia listed by the American Psychiatric Association in its
The cause of schizophrenia is unknown. Genetic factors appear to be involved in producing susceptibility to the condition, with studies among identical twins showing a 30%–50% concordance rate, a figure that has been confirmed by the results of adoption studies. Biochemical research suggests that high levels of the neurotransmitter dopamine, or excessive numbers of receptors for dopamine, may be at the root of schizophrenia. Medical imaging studies have revealed various physical and physiological anomalies in some patients. Other research has focused on mistiming of neural responses to stimuli in the brain. Many researchers maintain that a combination of influences, including such environmental factors as viral illness or malnutrition in the patient's mother during pregnancy, may lead to schizophrenia,
Antipsychotic drugs (see psychopharmacology), sometimes in conjunction with psychotherapy, have greatly improved the treatment of schizophrenia. Hospitalization is sometimes needed initially to provide basic personal needs (safety, food, and hygiene) while acute symptoms are treated. Most patients return to the community with varying degrees of independence and with good prospects for long-term remission of symptoms.
See R. Miller and S. Mason,
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