Two new JAMA Psychiatry meta-analyses link mental illness with COVID-19 death, with one also finding an association with hospitalization.
Patients with severe mental illness most vulnerable
The first study, published yesterday, was led by researchers from the CEReSS-Health Service Research and Quality of Life Center in Marseille, France. It consisted of 16 observational studies from seven countries involving 19,086 patients with COVID-19 and mental illness from December 2019 to July 2020. The countries were Denmark (1 study), France (2), Israel (1), South Korea (3), Spain (1), the United Kingdom (1), and the United States (7).
Regardless of the primary medical risk factors for severe COVID-19, patients with mental illnesses (eg, addiction, depression) were more likely to die of COVID-19 than their peers in pooled crude and adjusted analysis (crude odds ratio [OR], 1.75; adjusted OR [aOR], 1.38). Patients with the severe mental illnesses included in the study—schizophrenia and bipolar disorder—had the highest ORs for death, with a crude OR of 2.26 and an aOR of 1.67.
The higher rate of severe COVID-19 "suggests that other factors lead to this health inequity in patients with mental health disorders, including several factors such as barriers to access to care, social determinants of health, immunological disturbances, and the effects of psychotropic drugs," the study authors wrote.
The researchers said that patients with certain mental illnesses, such as depression, schizophrenia, and bipolar disorder, may have impaired immune defenses to begin with. They suggested that improved healthcare staff training on mental illnesses, broader implementation of advanced directives and do-not-resuscitate orders, and removing barriers to obtaining healthcare could improve patient care.
"These findings suggest that patients with COVID-19 and mental health disorders should be targeted as a high-risk population for severe forms of COVID-19, requiring enhanced preventive and disease management strategies," the authors wrote, adding that future research should delve into risk evaluation for COVID-19 patients with each type of mental illness.
Death risk similar to other chronic diseases
The second study was published today. It was led by University of Toronto researchers, included 21 studies of more than 91 million people with and without mood disorders. Twelve retrospective cohort studies, 8 retrospective case-control studies, and 1 exposure-crossover study from England (1), Israel (1), Italy (1), South Korea (2), Spain (2), Turkey (1), the United Kingdom (1), and the United States (12) were analyzed.
Compared with other COVID-19 patients, those with mood disorders were at significantly higher risk for hospitalization and death (OR for hospitalization, 1.31; OR for death, 1.51). The OR for death was similar to that for other risk factors for severe COVID-19 outcomes, including diabetes, liver disease, cancer, and obesity, the authors said.
There was no link between mood disorders and likelihood of SARS-CoV-2 infection (OR, 1.27) or severe events (OR, 0.94). The researchers pointed out the incongruity of having no association between mood disorders and severe events when there was a strong link to hospitalization and death.
"Possible explanations for this finding include interstudy variation in how severe events were defined, differences across studies in event reporting and coding, and heterogeneity in statistical approaches," they wrote. "Furthermore, the COVID-19 severe events analysis included a relatively small sample size."
The investigators said that people with mood disorders are at greater risk for infection because of impaired immune response, propensity toward substance abuse and predisposing chronic diseases (eg, obesity, cardiovascular disease), low ability to comply with public health measures, and social determinants of risk (eg, poverty, lower health literacy, tendency to live in congregate-care facilities).
"These results suggest that individuals with mood disorders should be categorized as an at-risk group for COVID-19 hospitalization and death, providing [a] basis for vaccine prioritization," the study authors wrote. "Future research should address whether COVID-19 vaccinations exhibit differential efficacy in persons with mood disorders and whether COVID-19 infection affects the longitudinal trajectory of the underlying mental disorder."