Is the Incidence of Psychosis the Same Across the World?

The conventional wisdom is that the incidence of psychotic disorders, such as schizophrenia and psychotic affective disorders, is the same in different countries. To explore this concept, an international consortium analyzed data from structured interviews and medical records of 2774 adults seeking treatment for a first episode of nonorganic psychosis (FEP) in 17 catchment areas in 5 European countries and Brazil (mean age, 30; nonaffective psychosis, 79% of patients; 12.94 million person-years of data).

Whereas the incidence of FEP was highest for men and women between the ages of 18 and 24, incidence subsequently declined rapidly in men but decreased more slowly in women, who experienced a secondary peak at ages 50 to 54. In analyses adjus…