COVID-19 survivors face a sharply elevated risk of developing psychiatric or neurologic disorders in the 6 months after they contract the virus – a danger that mounts with symptom severity, new research shows.
In what is purported to be the largest study of its kind to date, results showed that among 236,379 COVID-19 patients, one-third were diagnosed with at least 1 of 14 psychiatric or neurologic disorders within a 6-month span.
The rate of illnesses, which ranged from depression to stroke, rose sharply among those with COVID-19 symptoms acute enough to require hospitalization.
“If we look at patients who were hospitalized, that rate increased to 39%, and then increased to about just under 1 in 2 patients who needed ICU admission at the time of the COVID-19 diagnosis,” Maxime Taquet, PhD, University of Oxford (England) department of psychiatry, said at a media briefing.
Incidence jumps to almost two-thirds in patients with encephalopathy at the time of COVID-19 diagnosis, he added.
The study, which examined the brain health of 236,379 survivors of COVID-19 via a U.S. database of 81 million electronic health records, was published online April 6 in The Lancet Psychiatry.
High rate of neurologic, psychiatric disorders
The research team looked at the first-time diagnosis or recurrence of 14 neurologic and psychiatric outcomes in patients with confirmed SARS-CoV-2 infections. They also compared the brain health of this cohort with a control group of those with influenza or with non–COVID-19 respiratory infections over the same period.
All study participants were older than 10 years, diagnosed with COVID-19 on or after Jan. 20, 2020, and still alive as of Dec. 13, 2020.
The psychiatric and neurologic conditions examined included intracranial hemorrhage; ischemic stroke; parkinsonism; Guillain-Barré syndrome; nerve, nerve root and plexus disorders; myoneural junction and muscle disease; encephalitis; dementia; psychotic, mood, and anxiety disorders; substance use disorder; and insomnia.
The investigators used hospitalization, intensive care admissions, and encephalopathy as an indication of the severity of COVID-19 symptoms.
The study benchmarked the primary cohort with four populations of patients diagnosed in the same period with nonrespiratory illnesses, including skin infection, urolithiasis, bone fractures, and pulmonary embolisms.
Results showed that substantially more COVID-19 patients were diagnosed with a neurologic or psychiatric disorder compared with those with other respiratory illnesses.
“On average, in terms of the relative numbers, there was a 44% increased risk of having a neurological or psychiatric diagnosis after COVID-19 than after the flu and a 16% increased risk compared to other respiratory tract infections,” Dr. Taquet told reporters.
Health services should be prepared for an increase in psychiatric and neurologic issues in the months to come, he said, adding that further investigations are needed into why, and how, the coronavirus affects brain health.
Largest study to date
Although previous research suggests a link between the two, this is the largest study of its kind, examines a wider range of neurologic outcomes, and spans the longest time frame to date, said study coinvestigator Paul Harrison, BM BCh, associate head of the University of Oxford department of psychiatry.
There was a lower incidence of mood and anxiety disorders vs. neurologic disorders in patients with severe COVID-19 symptoms, a finding that Dr. Harrison said may indicate pandemic-related psychological stress is driving these disorders vs. biological factors.
“This paper follows up on an earlier study we did where we found much the same association, and our view is that a lot of the mental health consequences of COVID are … to do with the stress of knowing that one has had COVID and all the implications that go with that, rather than its being a direct effect, for example, of the virus on the brain, or of the immune response to the virus on the brain,” he added.
In contrast, neurologic diagnoses were more likely to be “mediated by some direct consequence of the COVID infection,” he added.
Psychosis and dementia, for instance, were less frequent in the overall COVID-19 population but became much more frequent among those with severe symptoms. The research team said these findings, along with those related to the incidence of ischemic stroke, were “concerning.”
“We found that 1 in 50 patients with COVID-19 go on to have an ischemic stroke in the 6 months after the COVID-19 illness,” Dr. Taquet told reporters. “And that rate increased to 1 in 11 patients if we look at patients with encephalopathy at the time of the COVID-19 diagnosis.”
Rates of brain hemorrhages also rose sharply among those with acute symptoms. Just over 1 in 200 total COVID-19 patients were diagnosed with this neurological condition, but that jumped to 1 in 25 of those who experienced encephalopathy at the time of their COVID-19 diagnosis.