Epidemiological factors associated with treated incidence of first-episode non-affective psychosis in Cantabria: insights from the Clinical Programme on Early Phases of Psychosis

Aim: The aim of the study was to analyse the treated incidence of schizophrenia in Cantabria (Northern Spain) and the sociodemographic risk factors associated with the illness onset. Methods: Data were obtained from patients included in the Cantabria's Clinical Programme on First-Episode Psychosis (schizophrenia spectrum DSM-IV diagnosis) from 2001 to 2005, from the Cantabria first-episode schizophrenia study (carried out between 1988 and 1989) and from the 2001 Spanish census. Results: Annual incidence was 1.38 per 10 000 inhabitants in the risk-ageperiod. Identified risk factors were male gender (relative risk (RR): 1.61), age 15-25 years (RR: 3.48), unemployment (RR: 2.82), single status (RR: 5.88), low educational level (RR: 4.38), urban environment (RR: 1.62) and cannabis consumption (odds ratio: 12.83). The incidence in females was significantly lower than the one obtained 15 years ago. Conclusions: The reported factors suggest that underlying biological and social factors modulate the risk of psychosis. This balance operates differently in males and females.