First-contact incidence of psychosis in north-eastern Italy: influence of age, gender, immigration and socioeconomic deprivation

Abstract

BackgroundConsiderable variations in the incidence of psychosis have been observed across countries, in terms of age, gender, immigration status, urbanicity and socioeconomic deprivation.AimsTo evaluate the incidence rate of first-episode psychosis in a large area of north-eastern Italy and the distribution of the above-mentioned risk factors in individuals with psychoses.MethodEpidemiologically based survey. Over a 3-year period individuals with psychosis on first contact with services were identified and diagnosed according to ICD-10 criteria.ResultsIn total, 558 individuals with first-episode psychosis were identified during 3 077 555 person-years at risk. The annual incidence rate per 100 000 was 18.1 for all psychoses, 14.3 for non-affective psychoses and 3.8 for affective psychoses. The rate for all psychoses was higher in young people aged 20–29 (incidence rate ratio (IRR) = 4.18, 95% CI 2.77–6.30), immigrants (IRR = 2.26, 95% CI 1.85–2.75) and those living in the most deprived areas (IRR = 2.09, 95% CI 1.54–2.85).ConclusionsThe incidence rate in our study area was lower than that found in other European and North American studies and provides new insights into the factors that may increase and/or decrease risk for developing psychosis.