Pre-pandemic psychiatric disorders and risk of COVID-19: a cohort analysis in the UK Biobank

Objective To determine the association between pre-pandemic psychiatric disorders and the risk of COVID-19. Design Community-based prospective cohort study. Setting UK Biobank population. Participants 421,048 participants who were recruited in England and alive by January 31st 2020, i.e., the start of COVID-19 outbreak in the UK. 50,815 individuals with psychiatric disorders recorded in the UK Biobank inpatient hospital data before the outbreak were included in the exposed group, while 370,233 participants without such conditions were in the unexposed group. Measurements We obtained information on positive results of COVID-19 test as registered in the Public Health England, COVID-19 related hospitalizations in the UK Biobank inpatient hospital data, and COIVD-19 related deaths from the death registers. We also identified individuals who was hospitalized for infections other than COVID-19 during the follow-up. Logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs), controlling for multiple confounders. Results The mean age at outbreak was 67.8 years and around 43% of the study participants were male. We observed an elevated risk of COVID-19 among individuals with pre-pandemic psychiatric disorder, compared with those without such diagnoses. The fully adjusted ORs were 1.44 (95%CI 1.27 to 1.64), 1.67 (1.42 to 1.98), and 2.03 (1.56 to 2.63) for any COVID-19, inpatient COVID-19, COVID-19 related death, respectively. The excess risk was observed across all levels of somatic comorbidities and subtypes of pre-pandemic psychiatric disorders, while further increased with greater number of pre-pandemic psychiatric disorders. We also observed an association between pre-pandemic psychiatric disorders and increased risk of hospitalization for other infections (1.85 [1.65 to 2.07]). Conclusions Pre-pandemic psychiatric disorders are associated with increased risk of COVID-19, especially severe and fatal COVID-19. The similar association observed for hospitalization for other infections suggests a shared pathway between psychiatric disorders and different infections, including altered immune responses.