In a study published in the journal JAMA Network Open on Sept. 30, Yale researchers analyzed patient data from the Yale New Haven Health System to investigate a possible link between prior psychiatric diagnosis and COVID-19 mortality.

Led by assistant professor of psychiatry Luming Li and Chief of Psychiatry at Yale New Haven Hospital John Krystal, researchers at the Yale School of Medicine looked at data from 1,685 patients hospitalized with COVID-19 during a two-month period and discovered that patients with a previous psychiatric diagnosis died from COVID-19 at a significantly higher rate than those without one.

“Controlling for medical illnesses, age, sex, and other factors, psychiatric disorders were associated with an increased mortality risk from COVID-19,” Krystal wrote in an email to the News. “This analysis was important because the patients with COVID-19 and psychiatric disorders tended to be older and to have more medical illnesses.”

Although the COVID-19 outbreak began almost a year ago, this is the first study to investigate the association of psychiatric diagnosis with COVID-19 mortality, to the researchers’ knowledge. Psychiatric disorders have previously been shown to affect mortality rates of other diseases, like heart disease. Given the widespread nature of the coronavirus pandemic, studying comorbidities — both physical and mental — has become imperative for proper treatment of high-risk populations.

The researchers were inspired to conduct this study after seeing many publications that analyzed mortality rates of patients with COVID-19 and associated risk factors yet failed to address prior psychiatric disorders in their data.

“None of the studies included the variable of prior psychiatric diagnoses,” Li wrote in an email to the News. “I found this to be troubling, especially since we know many patients with psychiatric comorbidities have poorer clinical outcomes (whether related to physical health conditions or all-cause mortality).”

Thus, this new study represents a new and important opportunity for researchers to gain a better understanding of COVID-19 and its relation to non-physical health.

Although the researchers established this correlation between prior psychiatric diagnosis and COVID-19 mortality rates, the underlying cause remains unclear. According to the paper, one possible explanation is that psychiatric disorders may be indicative of a larger inflammatory issue in the body that increases mortality rate. Another possibility is that psychiatric disorders and medications that treat them may magnify the body’s inflammatory response and thus compromise the immune system.

“We are increasingly appreciating that the boundaries of ‘mind’ and ‘body’ are breaking down,” Krystal wrote. “Psychiatric disorders, like depression, are associated with increased levels of inflammation in the body. On a long-term basis, this form of inflammation can worsen diseases affecting most organs of the body.”

However, it is clear that psychiatric diagnoses have a significant impact on the mortality rate of many diseases, including COVID-19. Krystal noted that the general attitude toward psychiatric disorders must shift to recognize their detrimental effect on physical medical conditions. Such results have long been ignored by society despite strong scientific evidence, causing the physical risks associated with psychiatric disorders to be underestimated.

Dwain Fehon, associate professor of psychiatry and chief psychologist for psychiatric services at the hospital, echoed this point and emphasized the importance of narrowing the gap between mental and physical health.

“Too often, the psychiatric and mental are not factored into the medical care that people receive,” Fehon said. “This article is a great contribution to the literature because it highlights the need to create more integrated health models for patients. We simply cannot focus on just the physical. We also need to look at the mental and social context of each individual.”

Li wrote that in the future, they hope to analyze patient data for different psychiatric diagnoses — something that they were unable to do in this study. Other possible avenues for future research include looking at the effect of substance abuse on COVID-19 mortality and considering controls such as body mass index.

Fehon also said that he looks forward to seeing more in-depth analyses of similar data to those used in the study, such as taking into account which patients were receiving medical care or were on psychotropic medications at the time. In addition, he said that more research must be done regarding the mental health needs of patients who survive COVID-19 and struggle with long-term health effects, like respiratory problems and issues with cognitive functioning.

According to the National Institutes of Health, an estimated 26 percent of adults in America suffer from a diagnosable psychiatric disorder.

Veronica Lee | veronica.lee@yale.edu

Veronica Lee covers breakthrough research for SciTech. She is a sophomore in Branford College majoring in molecular, cellular, and developmental biology.