Long Covid, often defined as symptoms occurring for 12 weeks or more after a Covid diagnosis, includes a range of symptoms from fatigue and shortness of breath to brain-related problems such as lack of mental clarity. Scientists have estimated that it could affect more than 100 million people worldwide. Researchers at the University of Oxford analyzed the electronic health records of 1.25 million people diagnosed with Covid and a matched control group consisting of an equal number of patients who had other respiratory infections. The data, covering 14 brain disorders, was provided by US-based global health research network TriNetX. The impact of Covid was most pronounced in people aged 65 and over, among whom 4.5 per cent developed dementia in the following two years, compared with 3.3 per cent of the control group. For psychotic disorders, the rates were 0.85 percent in Covid patients and 0.6 percent in controls. The most significant increased risk among younger adults ages 18 to 64 was cognitive deficit, sometimes called brain fog. It affected 6.4 percent of people who had had Covid in the previous two years and 5.5 percent of controls.

“The results have important implications for patients and health services, as they suggest that new cases of neurological disease linked to Covid infection are likely to emerge long after the pandemic subsides,” said Paul Harrison, senior author of the study published in The Lancet Psychiatry. But he added: “We are not talking about a tsunami of neurological and psychiatric diseases.” Max Taquet, who led the analysis, said two findings stood out in the study’s 185,000 patients under the age of 18. Children were twice as likely to develop epilepsy or seizures, he said — 2.6 percent developed the condition after Covid, compared to 1.3 percent after another respiratory infection. Second, Taquet added: “Children are three times more likely to have a psychotic disorder, even though this is rare – 18 in 10,000 in the two years after Covid.” But the study also showed that the impact of Covid was sometimes short-lived. “The excess risks of post-Covid depression and anxiety disappear within two to three months, with no overall excess of cases over the course of the two years,” Taquet said.

The researchers tried to distinguish between the effects of different Sars-Cov-2 variants, although there is inevitably less long-term data for more recently emerged strains, particularly Omicron. “The appearance of the Delta variant was associated with an increased risk for several conditions,” Taquet said. “With Omicron as the dominant variant, although we see much milder symptoms immediately after infection, similar rates of neurological and psychiatric diagnoses are seen as with Delta,” he added. Take said the findings suggest that the burden on health care systems may continue even with variants that are less severe in other respects. Looking at Covid more broadly, the Oxford scientists stressed that much research is still needed into all aspects of the condition, from definition and prevalence to biological causes and potential treatments. “My sense is that we know a lot less than we think we know about the long Covid,” Harrison said. “There are a lot more questions than answers,” Take agreed.

title: “Covid Can Cause Brain Disorders Two Years After Infection Study Finds Klmat” ShowToc: true date: “2022-11-11” author: “Glenn Smith”

Long Covid, often defined as symptoms occurring for 12 weeks or more after a Covid diagnosis, includes a range of symptoms from fatigue and shortness of breath to brain-related problems such as lack of mental clarity. Scientists have estimated that it could affect more than 100 million people worldwide. Researchers at the University of Oxford analyzed the electronic health records of 1.25 million people diagnosed with Covid and a matched control group consisting of an equal number of patients who had other respiratory infections. The data, covering 14 brain disorders, was provided by US-based global health research network TriNetX. The impact of Covid was most pronounced in people aged 65 and over, among whom 4.5 per cent developed dementia in the following two years, compared with 3.3 per cent of the control group. For psychotic disorders, the rates were 0.85 percent in Covid patients and 0.6 percent in controls. The most significant increased risk among younger adults ages 18 to 64 was cognitive deficit, sometimes called brain fog. It affected 6.4 percent of people who had had Covid in the previous two years and 5.5 percent of controls.

“The results have important implications for patients and health services, as they suggest that new cases of neurological disease linked to Covid infection are likely to emerge long after the pandemic subsides,” said Paul Harrison, senior author of the study published in The Lancet Psychiatry. But he added: “We are not talking about a tsunami of neurological and psychiatric diseases.” Max Taquet, who led the analysis, said two findings stood out in the study’s 185,000 patients under the age of 18. Children were twice as likely to develop epilepsy or seizures, he said — 2.6 percent developed the condition after Covid, compared to 1.3 percent after another respiratory infection. Second, Taquet added: “Children are three times more likely to have a psychotic disorder, even though this is rare – 18 in 10,000 in the two years after Covid.” But the study also showed that the impact of Covid was sometimes short-lived. “The excess risks of post-Covid depression and anxiety disappear within two to three months, with no overall excess of cases over the course of the two years,” Taquet said.

The researchers tried to distinguish between the effects of different Sars-Cov-2 variants, although there is inevitably less long-term data for more recently emerged strains, particularly Omicron. “The appearance of the Delta variant was associated with an increased risk for several conditions,” Taquet said. “With Omicron as the dominant variant, although we see much milder symptoms immediately after infection, similar rates of neurological and psychiatric diagnoses are seen as with Delta,” he added. Take said the findings suggest that the burden on health care systems may continue even with variants that are less severe in other respects. Looking at Covid more broadly, the Oxford scientists stressed that much research is still needed into all aspects of the condition, from definition and prevalence to biological causes and potential treatments. “My sense is that we know a lot less than we think we know about the long Covid,” Harrison said. “There are a lot more questions than answers,” Take agreed.