The treated incidence of psychotic disorders was shown to range from 6.0 to 46.1 per 100,000 person-years across various regions, according to the results of a recent study published in JAMA Psychiatry.
In the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU0GEI), researchers included 2774 individuals diagnosed with first-episode nonorganic psychotic disorders confirmed by the Operational Criteria Checklist in the study. The researchers included individuals from 2 regions in England, 3 in France, 3 in Italy, 2 in The Netherlands, 6 in Spain, and 1 in Brazil. They estimated the denominator populations of the various regions with national statistics.
A crude incidence of 21.4 cases per 100,000 person-years was estimated based on the 2774 patients identified during a total of 12.9 million person-years. After adjustment for age, sex, and race status, the incidence of psychotic disorders ranged from 6.0 cases per 100,000 person-years (Santiago, Spain) to 46.1 cases per 100,000 person-years (Paris, France).
The incidence rate ratio was higher in racial and ethnic minority groups (1.59; 95% CI 1.46-1.72) and lower in areas with more owner-occupied homes (0.76; 95% CI 0.70-0.83). The crude incidence of first-episode psychosis was highest in men age 18 to 24 (61.0 per 100,000 person-years).
Similar patterns of incidence were reported for nonaffective psychoses. For affective psychotic disorders, higher area-level unemployment was associated with a lower incidence rate ratio (0.3; 95% CI, 0.2-0.5).
The study investigators concluded that “treated incidence of psychotic disorders varied 8-fold between catchment areas after standardization for age, sex, and racial/ ethnic minority status. Rates were higher in younger people, men, racial/ethnic minorities, and areas with lower levels of owner-occupied housing, although substantial variation between catchment areas, and by broad diagnosis, remained.”
Jongsma HE, Gayer-Anderson C, Lasalvia A, et al. Treated incidence of psychotic disorders in the multinational EU-GEI study [published online December 6, 2017]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2017.3554