There is a dearth of epidemiological research on psychosis. Most of the published literature is either at a national scale, or compares urban and rural areas. Little is known about how psychosis rates vary within urban areas. Variation in rates would have implications for the aetiology of psychosis

We conducted a retrospective audit of the caseloads of the four Community Mental Health Teams (CMHTs) in Luton,UK. Caseloads were categorised by diagnoses recorded in the medical notes, and by patient age. We performed a descriptive analysis of the levels of psychosis in each CMHT, considered against multiple population parameters including deprivation and ethnicity as recorded in the 2001 UK census.

Areas with high indices of deprivation, and a large ethnic minority and migrant population, were found to have higher rates of psychosis. There was considerable overlap between areas with large ethnic minority and migrant populations, and areas of high deprivation. We were unable to disentangle this confounder in our audit.

Our findings are consistent with, and build on, the MRC Aetiology & Ethnicity of Schizophrenia & Other Psychoses (AESOP) study which showed variation in psychosis between three urban centers. The increased rates of psychosis observed in areas with large migrant and ethnic minority populations, and in areas of high deprivation, has implications for the planning of local services, and in further understanding the role of environmental factors in the aetiology of psychosis. There is a need for further prospective epidemiological studies at this geographical scale.