Changes and Trends in Healthcare Utilization for Child and Adolescent Mental Disorders before, during, and after the COVID-19 Pandemic

Background: This study examined whether the increasing trend in outpatient visits for mental disorders among children and adolescents was attributable to the impact of coronavirus disease of 2019 or whether it represented a continuation of pre-existing trends.Methods: An interrupted time-series analysis was conducted using national health insurance claims data to assess changes in the number of outpatient visits and total medical expenditure before and after the onset of COVID-19.Monthly data were analyzed after adjusting for seasonality and autocorrelation.In addition, demographic characteristics, including sex, age group, region, type of medical institution, and major diagnoses, were compared across the periods.Results: According to the demographic analyses, the proportion of females and school-aged children increased, whereas the proportion of adolescents showed a relative decrease.Attention-deficit/hyperactivity disorder accounted for an increased proportion of cases, whereas the proportions of some other disorders decreased.The proportion of clinical utilization increased, whereas that of higherlevel hospitals decreased.Regionally, the distribution of patients expanded beyond metropolitan areas, indicating a widespread pattern of healthcare utilization.Prior to the COVID-19 pandemic, both the number of outpatient visits and total medical expenditure showed a significantly increasing trend.Immediately after the onset of COVID-19, a significant decrease was detected in both outpatient visits (-14.1%) and medical expenditure (-15.2%).However, both indicators subsequently rebounded and resumed an increasing trend, although the rate of increase was significantly attenuated when compared with the pre-pandemic period.Conclusion: COVID-19 has led to a temporary decline in mental health service utilization among children and adolescents, followed by a recovery with a slower growth rate.These findings suggest that the increasing trend has persisted, although the pandemic has altered its trajectory.Given that childhood and adolescence are critical periods for early identification and intervention, the continued increase in outpatient visits underscores the urgent need for strategies focused on early prevention and timely intervention to address this growing demand.