Abstract
OBJECTIVE: Early life stress (ELS) is associated with increased risk for the development of major depressive disorder (MDD) in adulthood; however, the degree to which ELS is associated with an early onset of MDD (ie, during childhood or adolescence) is not known. In this meta-analysis, we estimated the associations between ELS and the risk for onset of MDD before age 18 years. In addition, we examined the associations between eight specific forms of ELS (ie, sexual abuse, physical abuse, poverty, physical illness/injury, death of a family member, domestic violence, natural disaster, and emotional abuse) and risk for youth-onset MDD. METHOD: We conducted a systematic search in scientific databases for studies that assessed both ELS and the presence or absence of MDD before age 18 years. We identified 62 journal articles with a total of 44,066 unique participants. We assessed study quality using the Newcastle-Ottawa Scale. When heterogeneous effect sizes were detected, we tested whether demographic and/or methodological factors moderated the association between ELS and MDD. RESULTS: Using a random-effects meta-analysis, we found that individuals who experienced ELS were more likely to develop MDD before the age of 18 years than were individuals without a history of ELS (odds ratio = 2.50; 95% confidence interval 2.08, 3.00). Separate meta-analyses revealed a range of associations with MDD: whereas some types of ELS (eg, poverty) were not associated with MDD, other types (eg, emotional abuse) were associated more strongly with MDD than was ELS considered more broadly. CONCLUSION: These findings provide important evidence that the adverse effect of ELS on MDD risk manifests early in development, prior to adulthood, and varies by type of ELS.