Geographical variation in incidence of first episode psychosis by place at birth vs place at onset and relationship to the social environment in the Cavan-Monaghan First Episode Psychosis Study (CAMFEPS)
Little is known about associations between the social environment and risk for psychosis within rural settings. This study sought to investigate whether such associations exist within an essentially rural context using a prospective dataset of unusual epidemiological completeness. Using the Cavan-Monaghan First Episode Psychosis Study database of people aged 16 years and older, both ecological analyses and multilevel modelling were applied to investigate associations between incidence of psychosis by both place at onset and place at birth and socio-environmental risk factors of material deprivation, social fragmentation and urban-rural classification across electoral divisions. For place at onset, the primary finding was an association between more deprived social contexts and higher rates of psychotic disorder, after adjustment for age and sex [all psychoses: incidence rate ratio (IRR) =1.12 (95% CI 1.03-1.23)]. These findings support an association between adverse socioenvironmental factors and increase in risk for psychosis by place at onset within an essentially rural environment. This study suggests that poorer social environments, rather than urbanicity per se, may be relevant to the incidence of psychosis, though such exposures may have greater impact in more urban settings.