The mental health of both moms and dads took a plunge during the pandemic, although the impact on fathers was slightly smaller. And school closures didn’t affect dads, but they were probably the cause of half of the mental health decline that mothers suffered, according to the new report from the Institute for Social & Economic Research. “This adds to a wider body of evidence showing that parents, especially mothers, have paid a heavy price during lockdown, with mothers being more likely than fathers to have left paid work, seen reductions in their working hours, and juggled work with caring responsibilities,” said Alex Beer, the welfare program head at the Nuffield Foundation in the UK. Mothers whose children were not prioritized to return to school — many of whom had to balance childcare, homeschooling, and their own work-from-home responsibilities — reported depression, trouble sleeping, and feelings of worthlessness, according to the study, which was based on six surveys of 1,500 parents of kids aged 4-12 in England taken from April to November 2020. Moms with at least one kid who was not prioritized to return to school were more likely to report “losing more sleep to worry, to feel constantly under strain; to feel like they can’t overcome their difficulties; to feel unhappy or depressed,” according to the report. They also had difficulty enjoying daily activities and lost self-confidence. “The impact of having children out of school on mothers’ mental health is substantial, and an important hidden cost of lockdown,” said Laura Fumagalli, a research fellow at the Institute for Social and Economic Research at the University of Essex. Mothers of kids less likely to return to school reported more loneliness, and feeling lonely was more associated with poor mental health than losing a job or having to work extra hours. The good news is that the mental health effects of school closures seem to be temporary. When kids returned to school in September, moms’ mental health began to improve. So as vaccinations drive down COVID cases and the vaccine begins to become available to young kids later this year and next year, moms can look forward to their mental health bouncing back.