New research from the United Kingdom compares the mental health of children and young people during the current COVID-19 pandemic with earlier results from 2017. In this study, researchers look at the mental health of more than 3,500 children. They found that rates of probable mental disorders have increased since 2017. In 2020, one in six of the participating children were identified as having a probable mental disorder, increasing from one in nine in 2017. The increase occurred in both boys and girls. Among 11 to 16 year old girls, 64% with a probable mental disorder had seen or heard an argument among adults in the household, compared with 47% of those unlikely to have a mental disorder. Children aged 5 to 16 years with a probable mental disorder were also more than twice as likely to live in a household that had fallen behind with payments, than children unlikely to have a mental disorder. The children and young people with a probable mental disorder were more likely to say that lockdown had made their life worse than those unlikely to have a mental disorder. Overall, it is clear that the COVID-19 pandemic has had a serious impact on the mental well-being of children and young people.