RESUMEN
BACKGROUND: COVID-19 pandemic stressors affected youth's mental health. This longitudinal study aims to explore these effects while considering predictive factors such as age and sex. METHODS: An initial sample of 1502 caregivers answered a longitudinal survey evaluating their youths' (4-17 years of age) emotional/behavioral symptoms using the Pediatric Symptom Checklist (PSC) screening tool. First assessment in May-July 2020 included the prior year's retrospective (TR) and since-lockdown-start (T0) PSC, followed by monthly evaluations until February 2021. RESULTS: A positive screening PSC (PSC+) was reported in 13.09% of cases at TR and 35.01% at T0, but the likelihood of PSC+ quickly decreased over time. At T0, a more pronounced impact was found on children (39.7%) compared to adolescents (25.4%); male children exhibited higher risk for a PSC+ at T0 and longitudinally than females. Adolescents presented a weaker effect of time-improvement. PSC+ at TR, experienced stressors, and caregiver's stress/depressive symptoms positively predicted PSC+ at T0 and longitudinally; adolescents' unproductive coping style predicted PSC+ at T0. CONCLUSION: The study shows a caregiver-reported increase in emotional/behavioral symptoms in youths during the COVID-19 pandemic, affecting predominantly younger children in the early stages and showing gradual improvement over time, albeit possibly slower in adolescents. IMPACT: The results show the anticipated surge in emotional and behavioral symptoms during the COVID-19 lockdown in youth reported by caregivers, followed by subsequent amelioration. Of greater significance, the study reveals a heightened impact on young children initially, yet it suggests a slower improvement trajectory in adolescents. The study also identifies risk factors linked to emotional and behavioral symptoms within each age group. Alongside the longitudinal approach, the authors underscore the remarkable inclusion of a significant representation of young children, an unusual feature in such surveys.