Much has been said about how the pandemic shutdown not only robbed kids of vital socialization and education, but also left them vulnerable to declining mental health , amplifying already debilitating struggles. But a new study, published in the journal JAMA Network Open, has also found a surprise: that the early COVID isolation may have actually helped improve, ever so slightly, the mental health struggles of some children. “We would have expected a lot of declines in mental health over time,” one of the lead authors, Kaja LeWinn, professor at the University of California School of Medicine, San Francisco, tells Fortune .

“We actually found some improvements, specifically for kids with significant behavioral problems.” Kids who started out with significant mental problems improved The study was based on the self-reported responses of over 1,200 children ages 6 to 17 who completed a checklist, before and during the pandemic, from the National Institute of Health’s Environmental influences on Child Health Outcomes ( ECHO ) Program. LeWinn and fellow lead author Courtney Blackwell, professor at Northwestern University Feinberg School of Medicine, pursued their research to understand what kind of impact the pandemic had on children, with the data from pre- and mid-pandemic.

Of the participants, those who entered the pandemic with significant, or “clinically meaningful” mental health problems—including anxiety, depression, or ADHD behaviors such as struggling to f.