Although empirical evidence has confirmed the causal relationship between childhood maltreatment and depression, findings are inconsistent on the magnitude of the effect of age of exposure to childhood maltreatment on psychological development. This systematic review with meta-analysis aims to comprehensively synthesize the literature on the relationship between exposure age of maltreatment and depression and to quantitatively compare the magnitude of effect sizes across exposure age groups. Electronic databases and grey literature up to April 6th, 2022, were searched for English-language studies. Studies were included if they: 1) provided the information on exposure age; and 2) provided statistical indicators to examine the relationship between childhood maltreatment and depression. Fifty-eight articles met eligibility criteria and were included in meta-analyses. Subgroup analyses were conducted based on subtypes of maltreatment and measurements of depression. Any kind of maltreatment (correlation coefficient [r] = 0.17, 95% CI = 0.15–0.18), physical abuse (r =0.13, 95% CI = 0.10–0.15), sexual abuse (r = 0.18, 95% CI = 0.15–0.21), emotional abuse (r = 0.17, 95% CI=0.11–0.23), and neglect (r = 0.08, 95% CI=0.06–0.11) were associated with an increased risk of depression. Significant differential effects of maltreatment in depression were found across age groups of exposure to maltreatment (Q = 34.81, p < 0.001). Age of exposure in middle childhood (6–13 years) had the highest risk of depression, followed by late childhood (12–19 years) and early childhood (0–6 years). Implications of the findings provide robust evidence to support targeting victimized children of all ages and paying closer attention to those in middle childhood to effectively reduce the risk of depression.

This study aimed to articulate the roles of social support and coping strategies in the relation between childhood maltreatment (CM) and subsequent major depressive disorder (MDD) with a comprehensive exploration of potential factors in a longitudinal community-based cohort. Parallel and serial mediation analyses were applied to estimate the direct effect (DE) (from CM to MDD) and indirect effects (from CM to MDD through social support and coping strategies, simultaneously and sequentially). Sociodemographic characteristics and genetic predispositions of MDD were considered in the modeling process. A total of 902 participants were included in the analyses. CM was significantly associated with MDD (DE coefficient (β) = 0.015, 95% confidence interval (CI) = 0.002∼0.028). This relation was partially mediated by social support (indirect β = 0.004, 95% CI = 0.0001∼0.008) and negative coping (indirect β = 0.013, 95% CI = 0.008∼0.020), respectively. Social support, positive coping, and negative coping also influenced each other and collectively mediated the association between CM and MDD. This study provides robust evidence that although CM has a detrimental effect on later-on MDD, social support and coping strategies could be viable solutions to minimize the risk of MDD. Intervention and prevention programs should primarily focus on weakening negative coping strategies, then strengthening social support and positive coping strategies.