The increased risk of depression and anxiety that patients experience after developing COVID-19 typically subsides within two months, according to a study published yesterday in The Lancet Psychiatry. However, patients may have an elevated risk for developing other psychiatric and neurological conditions, such as psychosis, brain fog, and seizures, for up to two years after their infections.
“The results have important implications for patients and health services as it suggests new cases of neurological conditions linked to COVID-19 infection are likely to occur for a considerable time after the pandemic has subsided,” study co-author Paul Harrison, B.M. B.Ch., of the University of Oxford said in a statement. “Our work also highlights the need for more research to understand why this happens after COVID-19, and what can be done to prevent or treat these conditions.”
Harrison and colleagues used data from the TriNetX electronic health record network, an international network of de-identified health care records from approximately 89 million patients (mostly from the United States, but also from Australia, Bulgaria, India, Malaysia, Spain, Taiwan, and the United Kingdom). The authors identified patients of any age who were diagnosed with COVID-19 between January 20, 2020, and April 13, 2022. These patients were matched with a cohort of patients diagnosed with any other respiratory infection.
The authors compared the risk of 14 neurological and psychiatric diagnoses for up to two years after infection among patients in the COVID-19 group with those in the other respiratory infection group. These diagnoses included anxiety disorder, mood disorder, psychotic disorder, insomnia, cognitive deficit (or brain fog), dementia, epilepsy or seizures, and ischemic stroke. To investigate the impact of different variants of COVID-19, the authors also compared patients diagnosed directly before and after the emergence of the alpha, delta, and omicron variants. The data were analyzed according to the patients’ ages: children (under 18 years), adults (18 to 64), and older adults (65 years and older).
Nearly 1.3 million patients with confirmed COVID-19 diagnoses were included in the study. Compared with adults diagnosed with any other respiratory disease, those who had had COVID-19 had a higher risk of brain fog (550 cases per 10,000 people in the control group vs. 640 cases per 10,000 people in the COVID-19 group) and muscle disease (32 cases per 10,000 people in the control group vs. 44 cases per 10,000 people in the COVID-19 group). In older adults who had had COVID-19, there was a higher occurrence of brain fog (1,540 cases per 10,000 people in the COVID-19 group vs. 1,230 cases per 10,000 people in the control group), dementia (450 cases per 10,000 people in the COVID-19 group vs. 330 cases per 10,000 people for dementia in the control group), and psychotic disorder (85 cases per 10,000 people in the COVID-19 group vs. 60 cases per 10,000 for psychotic disorder in the control group).
Among adults, the risk of mood or anxiety disorder diagnoses initially increased immediately after the COVID-19 infection but returned to the same risk level as other respiratory infections after 43 days for mood disorders and 58 days for anxiety disorders. After two years, there was no difference in the incidence of mood and anxiety disorders between the COVID-19 group and the group of patients diagnosed with any other respiratory infection.
Children were not at greater risk for mood or anxiety disorders following a COVID-19 diagnosis compared with children diagnosed with other respiratory infections. In the two years following COVID-19, however, children were more likely to be diagnosed with seizures (260 cases per 10,000 children for the COVID-19 group vs. 130 cases per 10,000 for the control group) and psychotic disorders (18 cases per 10,000 children for the COVID-19 group vs. 6 cases per 10,000 for the control group).
The delta variant was associated with significantly higher six-month risks of numerous disorders compared with individuals diagnosed with COVID-19 in the period just before delta emerged. Delta increased the risk of anxiety by 10%, insomnia by 19%, brain fog by 38%, epilepsy or seizures by 26%, and ischemic strokes by 27%. Delta was associated with a 40% lower risk of dementia, however. The risks during the omicron wave were similar to those when delta was the dominant variant.
“Our findings shed new light on the longer-term mental and brain health consequences for people following COVID-19 infection,” the study’s lead author Max Taquet, B.M. B.Ch., Ph.D., of the University of Oxford, said in the statement. “With omicron as the dominant variant, although we see much milder symptoms directly after infection, similar rates of neurological and psychiatric diagnoses are observed as with delta, suggesting that the burden on the healthcare system may continue even with variants that are less severe in other respects.”
For related information, see the Psychiatric News article “A Hazy Picture of Long-Haul COVID Begins to Emerge.”