Associations of childhood maltreatment types and timing with oxidative stress in formerly out-of-home placed young adults.

Background: Childhood maltreatment (CM) is associated with an increased risk of mental disorders, with oxidative stress (OS) being proposed as a potential mediator. However, it remains unclear whether exposure to specific types of CM during distinct developmental periods is associated with altered OS levels.Objective: This study aimed to explore the association between CM type and timing and OS in young adulthood.Methods: We studied 116 adults (30.5% women; mean age = 26.3 years) with previous residential care placements. CM exposure was assessed with the Maltreatment and Abuse Chronology of Exposure (MACE-X) scale, capturing types (parental abuse, neglect, peer violence, sexual abuse), overall severity, multiplicity, and duration. OS was measured via blood-based biomarkers: superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRed), and GPx/GRed ratio. Conditional random forest regressions and Spearman correlations were used to test effects of CM types and timing on OS.Results: Abuse and neglect during adolescence showed the highest variable importance (VI) for GRed. Abuse was associated with increased, and neglect with decreased GRed. Neglect at ages 8 and 12 showed the highest VI for GPx/GRed and were positively associated with the biomarker ratio. Furthermore, no significant associations were found between overall CM severity, multiplicity, or duration and any of the OS biomarkers examined.Conclusion: Type- and timing-specific characteristics may be important when examining associations between CM and OS in adulthood. More research is needed to test whether such associations can inform preventive strategies that aim to mitigate mental health impairments following CM.