Risk of severe COVID-19 infection in individuals with severe mental disorders, substance use disorders, and common mental disorders.

Objective: To evaluate the risk of severe COVID-19 in individuals with severe mental disorders, substance use disorders, and common mental disorders in the total adult population of Region Stockholm (N = 1,516,270), and to explore possible underlying mechanisms to the increased risk.

Methods: In this prospective cohort study, we examined the risk of hospitalization and treatment in an intensive care unit (ICU) with COVID-19, and death from COVID-19 for individuals with mental disorders. Associations were step by step adjusted for (1) sociodemographic/economic factors, (2) indicators of virus exposure, (3) somatic conditions, and (4) psychopharmacological treatment.

Results: In model 1 (adjusted for age, sex and living in a care home for elderly people), people with a mental disorder had increased risks for inpatient care (HR = 1.5), ICU care (HR = 1.5), and mortality (HR = 1.4) from COVID-19. There was an increased risk of dying from COVID-19 in all subgroups of mental disorders, particularly in people with a severe mental disorder (HR = 1.9). Different covariates had different effects on the association depending on the outcome and on sex, age, or psychiatric diagnosis of the participants.

Conclusion: People with mental disorders have an increased risk of severe COVID-19, including mortality. The increased risk was partly explained by the examined covariates.