A study of more than 1.25 million people diagnosed with COVID-19 suggests an elevated risk of developing certain neurological and psychiatric conditions for two years after COVID-19 infection compared to other respiratory infections.
Increased risk of certain neurological and psychiatric conditions (such as dementia, psychosis, “brain fog” and seizures) is even higher two years after COVID-19 compared to other respiratory infections, study suggests MQ-funded observational study of over 1.25 million patient health records published in The Lancet Psychiatry log. The increased risk of depression and anxiety in adults lasts less than two months before returning to levels comparable to those after other respiratory infections.
In another recent article published in brain communications by the same researchers, they found support for the hypothesis that brain fog, or cognitive decline, is associated with damaged small blood vessels in the brain caused by COVID-19.
Since the onset of the COVID-19 pandemic, there has been growing evidence that survivors may be at increased risk for neurological and psychiatric disorders. A previous study reported that COVID-19 survivors are at increased risk for several neurological and mental health problems in the first six months after infection. However, until now, there have been no large-scale data examining the risks of these diagnoses over a longer period of time. This study was also the first large-scale study to examine the risk of neurological and mental disorders after COVID-19 in children and to assess how the risks change with the emergence of new variants.
Professor Paul Harrison, lead author of the study, from the University of Oxford, UK, says:
In addition to confirming previous findings that COVID-19 may increase the risk of certain neurological and psychiatric conditions in the first six months after infection, this study suggests that some of these increased risks may last for at least two years. The results have important implications for patients and health services as they suggest that new cases of neurological disorders related to COVID-19 infection are likely to occur for a considerable time after the pandemic is over. Our work also highlights the need for further research to understand why this happens after COVID-19 and what can be done to prevent or treat these conditions.
The study analyzed data on 14 neurological and psychiatric diagnoses collected from electronic health records, mostly from the United States, over a two-year period. Of these 1,284,437 people, on or after January 20, 2020, confirmed SARS-CoV-2 infection was included in the study: 185,748 children (under the age of 18), 856,588 older adults aged 18 to 64 and 242,101 adults over 65. These individuals were matched with an equal number of patients with another respiratory infection to serve as a control group.
Records of COVID-19 patients infected during different pandemic waves were also compared to study differences in the impact of alpha, delta and omicron variants on the risk of neurological and psychiatric diagnoses. People who were first diagnosed with COVID-19 during the period when a particular variant was dominant (alpha: 47,675 people, delta: 44,835 people, omicron: 39,845 people) were compared to a control group from the same number of individuals who had a first diagnosis of COVID-19 in the period just before the emergence of this variant.
The study found that, in adults, the risk of having a diagnosis of depression or anxiety initially increased after SARS-CoV-2 infection, but returned to the same as with other respiratory infections. after a relatively short period (depression at 43 days, anxiety at 58 days.) After the initial increase, the odds of being diagnosed with depression or anxiety fell below those of the control group, which means that after two years, there was no difference in the overall incidence of depression and anxiety between the COVID-19 group and the other respiratory infections group (in adults aged 18-64 in both groups, within two years of infection, there were about 1,100 cases of depression per 10,000 people and about 1,800 cases of anxiety per 10,000 people).
However, the risk of being diagnosed with some other neurological and mental health conditions was still higher after COVID-19 than for other respiratory infections at the end of the two-year follow-up. Adults aged 18 to 64 who had COVID-19 up to two years previously had a higher risk of cognitive impairment, or “brain fog” (640 cases per 10,000 people) and muscle disease (44 cases per 10,000), compared with those who had other respiratory infections up to two years previously (550 cases per 10,000 of “brain fog” and 32 cases per 10,000 of muscle disease). Among adults aged 65 and over who had contracted COVID-19 up to two years previously, there was a higher frequency of “brain fog” (1,540 cases per 10,000 people), dementia (450 cases per 10,000 people) and psychotic disorders (85 cases per 10,000 people). 10,000 people) compared to those who previously had a different respiratory infection (1,230 cases per 10,000 for “brain fog”, 330 cases per 10,000 for dementia and 60 cases per 10,000 for psychotic disorder).
The likelihood of most neurological and psychiatric diagnoses after COVID-19 was lower in children than in adults, and they were no more at risk for anxiety or depression than children who had other respiratory infections. . However, like adults, children were more likely to be diagnosed with certain conditions, including seizures (260 cases per 10,000 children for the COVID-19 group; 130 cases per 10,000 for the control group) and disorders psychotics (18 cases per 10,000 children for the COVID-19 group; 6 cases per 10,000 for the control group), over the two years following COVID-19.
Little change was observed in the risks of neurological and psychiatric diagnoses six months after COVID-19 just before and just after the emergence of the alpha variant. However, emergence of the delta variant was associated with significantly higher risks of anxiety (10% increased risk), insomnia (19% increased risk), cognitive impairment (38% increased risk), epilepsy or seizures (26% increased risk). risk), and ischemic stroke (27% increased risk), but lower dementia risk (40% reduced risk), compared to people diagnosed with COVID-19 just before the delta wave. 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 consequences on people’s mental and brain health following a COVID-19 infection. It’s good news that the higher risk of being diagnosed with depression and anxiety after COVID-19 is relatively short-lived and that there is no increased risk of these diagnoses in children. However, it is concerning that some other conditions, such as dementia and seizures, continue to be diagnosed more frequently after COVID-19, even two years later.
Says Dr Max Taquet of the University of Oxford, who led the analyses. “Emergence of the delta variant has been associated with increased risk for several conditions; However, it is important to note that the overall risk of these conditions is still low. With omicron as the dominant variant, although we observe 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 less severe variants in other respects. .”
In a separate study, a particular type of anticonvulsant drug, called phenytoin, was found to reduce the risk of cognitive impairment by 22-27% in people infected with COVID-19, provided it was administered to the good time.
According to this research, also funded by MQ, this may indicate that brain fog is, at least in part, due to damage to small blood vessels in the brain. Maxime Taquet, lead author of this study, says
These findings shed new light on the possible causes of brain fog and how to prevent it in the future. We certainly don’t suggest people start taking phenytoin if they have COVID. The purpose of this study was to identify possible mechanisms, not possible treatments.