Psychotic disorders are severe mental health conditions frequently associated with long-term disability, reduced quality of life and premature mortality. Early Intervention in Psychosis (EIP) services aim to provide timely, comprehensive packages of care for people with psychotic disorders. However, it is not clear which components of EIP services contribute most to the improved outcomes they achieve.

We aimed to identify associations between specific components of EIP care and clinically significant outcomes for individuals treated for early psychosis in England.

This national retrospective cohort study of 14 874 EIP individuals examined associations between 12 components of EIP care and outcomes over a 3-year follow-up period, by linking data from the National Clinical Audit of Psychosis (NCAP) to routine health outcome data held by NHS England. The primary outcome was time to relapse, defined as psychiatric inpatient admission or referral to a crisis resolution (home treatment) team. Secondary outcomes included duration of admissions, detention under the Mental Health Act, emergency department and general hospital attendances and mortality. We conducted multilevel regression analyses incorporating demographic and service-level covariates.

Smaller care coordinator case-loads and the use of clozapine for eligible people were associated with reduced relapse risk. Physical health interventions were associated with reductions in mortality risk. Other components, such as cognitive–behavioural therapy for psychosis (CBTp), showed associations with improvements in secondary outcomes.

Smaller case-loads should be prioritised and protected in EIP service design and delivery. Initiatives to improve the uptake of clozapine should be integrated into EIP care. Other components, such as CBTp and physical health interventions, may have specific benefits for those eligible. These findings highlight impactful components of care and should guide resource allocation to optimise EIP service delivery.