Epidemiology of schizophrenia: review of findings and myths

Abstract

By describing patterns of disease distribution within populations, identifying risk factors, and finding associations, epidemiologic studies have contributed to the current understanding of schizophrenia. Advanced paternal age and the association with autoimmune diseases are some of the newly described epidemiologic findings shaping the current definition of schizophrenia. Although early intervention strategies have gained momentum, primary prevention of schizophrenia still seems a very distant aspiration. This article reviews the major epidemiological features of schizophrenia, with particular attention to the recent advances using population-based data. It also discusses some pervasive misconceptions about schizophrenia epidemiology, such as universal distribution and gender equality.

FIGURE 1. Incidence of Schizophrenia in Selected Studies published after 1985

Criteria: study focus is the general population of a defined geographic area; diagnosis is made by a psychiatrist; case finding includes inpatient and outpatient services; greater than 25000 person years of risk in age group studies.

FIGURE 2. Community survival in schizophrenia (1, 5, 10, and, 15 represent the number of hospital discharges)

Source: Mortensen and Eaton (1994).