This longitudinal study examined how early childhood mental health evolved across the pre-, during-, and post-COVID-19 periods in a Chilean birth cohort. The objective was to characterize distinct co-occurring trajectories of internalizing and externalizing problems from ages three to six and to identify early and pandemic-related risk factors associated with higher-risk trajectories.
The analytic sample included N = 468 children (48.9% girls), with 19.2% of children born to migrant mothers. Data were collected longitudinally across ages three to six, covering timepoints before the pandemic, during the pandemic, and after the acute pandemic period. The publication details reported are Child Development, 2026; DOI 10.1093/chidev/aacaf035; PMID 41837774.
Investigators applied group-based multitrajectory modeling to jointly model trajectories of internalizing and externalizing symptoms across the observed time window. This method identifies subgroups with distinct longitudinal patterns in multiple symptom domains, enabling the detection of heterogeneous developmental courses in early childhood mental health.
Five distinct multitrajectory profiles were identified. Three profiles, composing 82.9% of the sample, were characterized by relatively lower symptom levels across observation points. Two profiles, representing 17.1% of participants, were classified as higher-risk groups indicated by persistent or escalating co-occurring internalizing and externalizing problems through age six. The study reports that children who already showed elevated symptoms prior to the pandemic tended to continue experiencing difficulties across the follow-up period.
Among predictors measured before the pandemic, greater child negative affect and higher levels of maternal depressive symptoms were associated with membership in the higher-risk trajectory groups. These findings indicate that prepandemic emotional vulnerability in the child and caregiver mental health status were important determinants of continued or worsening symptomatology.
The study identified pandemic-specific stressors that predicted higher-risk group membership. In particular, exposure to hostile parenting during the pandemic and household income loss were linked to elevated likelihood of belonging to the higher-risk trajectories. These pandemic-era adversities contributed beyond prepandemic risks to differentiate children's mental health courses.
Beyond prepandemic maternal depressive symptoms, deterioration in maternal mental health during the pandemic further contributed to escalation of child symptoms. The authors reported that maternal mental health changes over the pandemic period were associated with worsening trajectories in children's emotional and behavioral functioning.
The findings underscore heterogeneity in early childhood responses to a major population-level stressor. Key clinical implications drawn from the study include the importance of early identification of children with elevated internalizing and externalizing symptoms, and routine assessment of caregiver mental health and pandemic-related adversities (for example, income loss and family stress). Interventions that address parental mental health and reduce hostile parenting practices, and supports that mitigate financial strain, are highlighted as relevant targets given their association with higher-risk trajectories.
The abstract and plain language summary summarize core results but do not provide granular methodological or contextual details such as measurement instruments, exact timing of assessments, or effect sizes; those details were not reported in the PubMed abstract provided here. The study reports no conflicts of interest. Overall, approximately one in six children in this cohort experienced persistent or worsening co-occurring internalizing and externalizing problems spanning the pandemic period, with both prepandemic vulnerabilities and COVID-19–related stressors predicting membership in these higher-risk groups. The authors conclude that early detection of psychosocial risk factors and support for families are key to preventing long-term emotional and behavioral difficulties in young children.
Primary citation information reported in the source: Marigen Narea et al., Child Development, 2026; DOI 10.1093/chidev/aacaf035; PMID 41837774. No additional references or numerical effect estimates were reported in the provided source material.