Introduction:This study addresses the scarcity of research on the characteristics of young children's internalizing problems in Low and Middle-Income Countries (LMICs) through a systematic review of pre-pandemic literature. It aims to provide essential insights into understanding, preventing, and intervening in internalizing problems among young children. Additionally, it lays the groundwork for future studies to explore the effects of the pandemic on mental health in young children, including potential changes in the prevalence and nature of internalizing problems.Methods:The systematic review included thirty-one studies from LMIC studies published in English, Spanish, or Portuguese before March 2020 focusing on predictors, mediators, and characterizations of internalizing symptoms in preschoolers. The studies were classified by region to identify commonalities, interests, and differences.Results:The review revealed a significant disparity in research representation across regions, with the Americas being the most extensively studied and regions like the Eastern Mediterranean and Southeast Asia lacking adequate research. Validation of behavioral problem scales in LMICs was limited, posing challenges to accurate measurement. However, findings highlighted common risk factors such as maternal characteristics and environmental influences.Conclusions:Despite limitations, this review emphasizes the urgent need for comprehensive research on internalizing problems in preschoolers, particularly in LMICs. Broadening linguistic inclusion criteria and prioritizing validation efforts for behavioral problem scales are crucial steps towards addressing research gaps. Furthermore, highlighting common risk factors and patterns across regions underscores the importance of collaborative efforts to inform effective interventions and support child mental health globally.
