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Schizophrenia in adults: Epidemiology and pathogenesis

Bernard A Fischer, MD
Robert W Buchanan, MD
Section Editor
Stephen Marder, MD
Deputy Editor
Richard Hermann, MD


Schizophrenia is among the most disabling and economically catastrophic medical disorders, ranked by the World Health Organization as one of the top ten illnesses contributing to the global burden of disease [1].

Characteristics of schizophrenia typically include positive symptoms, such as hallucinations or delusions; disorganized speech; negative symptoms, such as a flat affect or poverty of speech; and impairments in cognition, including attention, memory, and executive functions. The illness is commonly associated with impairments in social and occupational functioning [2]. Antipsychotic medications are first-line treatment for schizophrenia. Evidence-based psychosocial interventions in conjunction with pharmacotherapy can help patients achieve recovery.

This topic discusses the epidemiology and pathogenesis of schizophrenia. Clinical manifestations, assessment, diagnosis, and course of schizophrenia are discussed separately. Anxiety and depression in schizophrenia are discussed separately. Psychosocial and pharmacologic treatments for schizophrenia are discussed separately, including long-acting antipsychotics, clozapine, and management of antipsychotic side effects. Evaluation and management of treatment resistant schizophrenia are also reviewed separately. (See "Schizophrenia in adults: Clinical manifestations, course, assessment, and diagnosis" and "Pharmacotherapy for schizophrenia: Acute and maintenance phase treatment" and "Pharmacotherapy for schizophrenia: Side effect management" and "Pharmacotherapy for schizophrenia: Long-acting injectable antipsychotic drugs" and "Psychosocial interventions for schizophrenia" and "Depression in schizophrenia" and "Anxiety in schizophrenia" and "Evaluation and management of treatment-resistant schizophrenia".)


Schizophrenia occurs throughout the world. The prevalence of schizophrenia (ie, the number of cases in a population at any one time point) approaches 1 percent internationally. The incidence (the number of new cases annually) is about 1.5 per 10,000 people [3]. Age of onset is typically during adolescence; childhood and late-life onset (over 45 years) are rare. Slightly more men are diagnosed with schizophrenia than women (on the order of 1.4:1) [4], and women tend to be diagnosed later in life than men. Modal age of onset is between 18 and 25 for men and between 25 and 35 for women, with a second peak occurring around menopause [5]. There is also some indication that the prognosis is worse in men [6,7].

Co-occurring conditions — People with schizophrenia have higher rates of several psychiatric disorders than people without schizophrenia, including:

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Literature review current through: Dec 2017. | This topic last updated: Mar 17, 2017.
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