The effect of the COVID-19 pandemic on the treated incidence of psychotic disorders in South London

Evidence on the impact of the COVID-19 pandemic on psychotic disorders is so far scarce. We conducted an incidence study to ascertain rates of first-episode psychosis (FEP) before and during the COVID-19 pandemic in South London.We screened clinical records of individuals living in the London boroughs of Southwark and Lambeth who were referred to the early intervention services before (from 1/3/2019 to 28/2/2020) and during (from 1/3/ 2020 to 28/2/2021) the COVID-19 pandemic. We used the Office for National Statistics to determine the population at risk. We computed crude and sex-age standardised FEP incidence per 100,000 person-years. We used Poisson regression to calculate the incidence rate ratio (IRR) across the COVID-19 pandemic.A total of 321 incident cases of FEP were identified during the COVID-19 pandemic, accounting for a crude rate of 69.8 (95% CI 62.1-77.4) per 100,000 person-years. The crude rate for the year before was 47.5 (95% CI 41.2-53.8). The incidence variation between the two years accounted for an adjusted IRR of 1.45 (95% CI 1.22-1.72). The pandemic was accompanied by a 45% spike in the rates of first-episode psychosis. This finding should inform public health research and demonstrate the need for adequate resources for secondary care.