Changes in internalizing and externalizing problems in Dutch children and adolescents receiving outpatient youth care before and during the COVID-19 pandemic

The COVID-19 pandemic significantly impacted the mental health of children and adolescents, but its effects on treatment outcomes in youth care remain unclear. This study examines whether the pandemic influenced treatment outcomes for internalizing and externalizing problems in children receiving outpatient youth care. We analyzed data from three groups of children who received outpatient youth care (N = 1090, M_age = 12.85): those treated entirely before the pandemic, those who transitioned into pandemic-related measures during treatment, and those treated entirely during the pandemic. The Child Behavior Checklist was used to assess internalizing and externalizing problems at the start and end of treatment. Repeated measures ANCOVAs and χ² tests of independence were conducted to evaluate changes in problem severity and clinical status, and ANCOVAs were used to compare between-group differences. The results suggest that while overall treatment outcomes were not directly affected by the pandemic, fewer children treated during the pandemic recovered from externalizing problems compared to those treated before the pandemic. Additionally, children treated entirely during the pandemic exhibited higher levels of internalizing and externalizing problems at both the start and end of treatment, and those transitioning into the pandemic also had elevated externalizing problems at both time points. Although the pandemic did not affect the change in problems during treatment, the increased severity of issues at both the start and end of treatment indicates a deterioration in child mental health since the pandemic. Appropriate support, preventive interventions, and regular monitoring of mental health problems may mitigate future impacts.