A new study suggests that reopening schools after pandemic closures can significantly benefit children’s mental health, providing insights for future public health planning. Researchers emphasize that policies must balance infection control with access to the social and emotional support schools offer. The study was published online today in Epidemiology.
The analysis used data from 224 school districts across 24 California counties, spanning March 2020 to June 2021. Health claims from the Healthcare Integrated Research Database and the California Department of Education covered 185,735 children aged 5 to 18, totaling over 2.1 million observations.
Using a difference-in-differences approach, researchers examined how staggered school reopenings—from August 2020 through June 2021—affected diagnoses of depression, anxiety, and attention-deficit/hyperactivity disorder (ADHD), as well as mental health–related healthcare spending. The staggered reopenings allowed comparison of outcomes from the 13 months before the pandemic to nine months after schools reopened.
Overall, mental health diagnoses increased by 25% during the study period, from 2.8% to 3.5%, while monthly mental health–related medical costs rose 30.5%, from $49.50 to $64.60. However, by the ninth month after schools reopened, diagnoses of any mental health condition decreased by 1.2 percentage points (95% CI, –1.59 to –0.74), with depression showing the largest reduction of 0.6 percentage points (95% CI, –1.0 to –0.3). In practical terms, the probability of a student being diagnosed with a mental health condition dropped from 60% to 43%.
Examining specific diagnoses, declines in depression, anxiety, and ADHD were observed by the fifth month after reopening. Anxiety rose slightly between months six and seven before dropping sharply by month nine, while depression remained steady through month seven before falling. ADHD diagnoses fluctuated, first increasing between months five and seven, then decreasing between months seven and eight, and rising again by month nine.
Mental health–related spending also declined. By month nine, total nondrug medical costs dropped 10.6% (95% CI, –13.4% to –7.8%), drug costs fell 7.5% (95% CI, –12.5% to –2.5%), and ADHD drug costs decreased 5.0% (95% CI, –8.2% to –1.8%).
The study found that female students benefited more from school reopenings than males. By month nine, mental health diagnoses among females decreased 1.9 percentage points, while ADHD diagnoses remained unchanged. Female students’ medical and pharmacy costs fell 15.3% and 9.9%, respectively, compared with smaller reductions among male students.
The study population had a mean age of 11.6 years, with 49% female, 7.5% living in rural areas, and 61.3% from the highest Census income quartile. Nearly half (49.5%) had healthcare costs related to mental health diagnoses.
“Future public health responses should prioritize safe school reopenings and ensure children have access to the social and emotional support schools provide,” said senior author Rita Hamad, PhD, MD, MPH, of the Harvard T.H. Chan School of Public Health. “Policies should focus not only on infection control but also on the mental well-being of children, recognizing schools as critical support systems.”
The authors also noted that pandemic-related school closures negatively affected mental health through disrupted social interactions, irregular sleep, increased screen time, poorer diets, learning difficulties, socioeconomic hardship, loss of school-based services, and gender-related social pressures.
Limitations of the study include potential confounding from relaxed COVID-19 restrictions, declining infection rates, changes in telehealth access, and care-seeking behavior. The findings may also be specific to California and may not generalize nationally or internationally.
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