San Francisco, Nov 12 : While Covid-19 lockdowns had a major impact on children's mental health, new research now highlighted how those impacted ADHD (attention deficit hyperactivity disorder) risk in 10-year-old children. According to a study by the University of Copenhagen, kids in this age group who already had a genetic risk of developing ADHD witnessed a "significant increase" in diagnoses after the pandemic. Researchers analysed two groups of children, a total of 593, in 2019 and 2021, reports Fox News. They discovered that children with polygenic risk scores (PRS) for behaviour and attention problems had a significant increase in ADHD diagnoses after the lockdown. Those who had low PRS did not show that increase. (Polygenic risk scores measure an individual's genetic disposition to any given disease.) "We found that the results from our data, regarding our cohort in Denmark, replicated what many studies had already reported with other samples -- the lockdown related to the Covid-19 pandemic was associated with an increase in mental health problems in children," Maria Hernandez Lorca, lead author of the study and a researcher at the University of Copenhagen, was quoted as saying. "The results showed that only the group of children with the high genetic risk for ADHD displayed an increase in mental health problems. Our findings suggest that under a stressor, (like) the lockdown, your genetic makeup significantly influences your mental health," she added. Lorca also acknowledged that the study did have some limitations. "The children examined before and after the lockdown were not the same children. Therefore, we cannot conclusively state that the lockdown increased mental health problems -- rather, we observed more mental health problems," she pointed out. Another potential limitation, Lorca mentioned, is that "even though the psychopathological examination was conducted face-to-face with the child and was very thorough, it relied partially on parental questionnaires". She also added, "With parents spending more time with their children during the lockdown, they may have become more aware of pre-existing problems". /IANS