(Bloomberg) -- The largest study of long Covid in children found kids can experience symptoms persisting at least two months, but researchers say the indirect effects of the pandemic probably carry a more lasting impact.

Children who test positive for Covid are more likely to experience at least one long-lasting symptom than children who have never been diagnosed, according to findings published in The Lancet Child & Adolescent Health journal. But the study results can be seen as “reassuring,” Maren Rytter of the University of Copenhagen wrote in comments accompanying the data.  

The study conducted in Denmark is aimed at helping parents, doctors and policy makers understand the risks for children as the window to conduct such comparative research closes because the vast majority of kids have now had Covid, the authors wrote. 

In children 12 to 14 years old, quality-of-life scores were actually higher and reports of anxiety were lower for those who had tested positive for Covid. That’s likely because kids who hadn’t been exposed to the virus “experienced fear of the unknown” and more protective restrictions, the authors said.

Headaches, mood swings, abdominal pain and fatigue -- complaints often linked to long Covid -- were slightly more frequent in kids who have been infected, the study shows, but they can also result from common childhood ailments unrelated to the disease. 

For most children, symptoms are “more likely to be caused by something other than Covid-19 and, if they are related to Covid-19, they are likely to pass with time,” Rytter wrote. 

Although data show the chances of children experiencing long Covid are low, it must be recognized and treated seriously, the authors said. Another study published in March gave more concerning findings. The so-called meta analysis found that about a quarter of children and adolescents infected experienced long Covid. 

Rytter, who wasn’t involved in the study, pointed to school closures, social isolation and two years of reduced exposure to common pathogens as among factors that would likely have a more lasting impact on children. 

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