Incidence of first episode psychosis in children and young people in England: sociodemographic variation and the role of ethnicity and socioeconomic deprivation

First episode psychosis (FEP) refers to the initial occurrence of a psychotic experience - including hallucinations, delusions, disorganized thinking, disorganized behaviour, or negative symptoms - in an individual with no prior history of psychotic disorder that typically requires clinical intervention. In this study, we will estimate the treated incidence of FEP through linked national hospital admissions and community mental health services records. Cases will be identified through: (1) first hospital admission with a psychotic disorder diagnosis, (2) acceptance onto Early Intervention in Psychosis (EIP) services, the NHS specialist community treatment pathway for FEP, with assignment to an FEP care cluster, or (3) confirmed referral and entry into EIP treatment. Psychotic disorders, such as schizophrenia, account for 24.5% of all psychiatric admissions among individuals aged 10 to 18 years in the UK. The situation is particularly concerning among minoritised ethnic groups, as individuals from minoritised ethnic backgrounds in the UK are more likely to be diagnosed with psychotic disorders than individuals from White British groups. Since susceptibility to psychotic disorders often develops during early life, and is strongly linked to social determinants of health, it is crucial to investigate the underlying causes of FEP among young people. Aim: Using novel data linkage of health and educational records through the ECHILD data resource, we will examine the treated incidence of FEP in children and young people (CYP) in England by ethnic group, as well as age, sex/gender, and other sociodemographic characteristics, using linked data to identify cases across multiple healthcare settings (hospital admissions and community mental health services). We will investigate whether observed ethnic disparities in the treated incidence of FEP are mediated by socioeconomic deprivation and/or acculturation factors (English language proficiency).