Incidence and diagnostic diversity in first-episode psychosis.

OBJECTIVE: To investigate the incidence and range of diagnostic groups in patients with first-episode psychosis (FEP) in a defined geographical area. METHOD: An observational database was set up on all patients aged 16 years and over presenting with FEP living in a county in Northern England between 1998 and 2005. RESULTS: The incidence of all FEP was 30.95/100,000. The largest diagnostic groups were psychotic depression (19%) and acute and transient psychotic disorder (19%). Fifty-four per cent of patients were aged 36 years and over. Patients with schizophrenia spectrum disorder only accounted for 55% of cases. CONCLUSION: This clinical database revealed marked diversity in age and diagnostic groups in FEP with implications for services and guidelines. These common presentations of psychoses are grossly under researched, and no treatment guidelines currently exist for them.