Neighbourhood-level variations in psychosis prevalence and involuntary psychiatric admissions

Studies have highlighted geographical variations in psychosis and involuntary psychiatric admissions. However, the association of neighbourhood-level factors on these variations remains underexplored. Aims To investigate geographical variations in psychosis prevalence and involuntary admissions, and associations with neighbourhood variables, in a cohort accessing secondary mental health services in South London. Method We used de-identified patient data from the Clinical Records Interactive Search (South London and Maudsley NHS Foundation Trust) linked to neighbourhood-level exposures. Age- and sex- standardised prevalence of psychosis (SPP) and involuntary admissions were calculated at the area level, mapped, and analysed for spatial autocorrelation. Ecological associations between neighbourhood variables and SPP were assessed using linear regression, while multilevel modelling was used to assess relationships between the neighbourhood variables and involuntary admissions. Results Among 18,917 participants with psychosis, we observed geographical clustering of psychosis and involuntary admissions. We found higher psychosis prevalence was associated with residence in areas with higher levels of deprivation, greater population density, higher social fragmentation, higher proportions of residents from minoritised ethnic backgrounds, and higher levels of reported crime. Lower prevalence was noted in areas with higher proportions of green spaces. We found higher involuntary admissions among ethnically minoritised groups, individuals who were previously married, those with substance misuse histories, and individuals receiving state benefits. Conclusions Geographical variations in psychosis prevalence and involuntary admissions underscore the importance of monitoring and addressing both individual- and neighbourhood-level variables to inform targeted service provision for people with psychosis.