Biological Embedding of Child Maltreatment: A Systematic Review of Biomarkers and Resilience in Children and Youth

Objective: Child maltreatment (CM) is a widespread problem associated with poor mental and physical health outcomes. The underlying mechanisms of this link are not always well understood, however certain biological changes observed in maltreated individuals may play a role in connecting experience and outcome. This review specifically focuses on 2 markers of biological embedding, DNA methylation (DNAm) and telomere length (TL) in maltreated children and youth. As biomarker changes are not uniform among maltreated children, we additionally discuss biological and environmental resilience factors that may contribute to variability. Method: We conducted a systematic review of Medline, Embase and PsycINFO databases for studies examining DNAm and/or TL in maltreated children and youth. Methodological quality of the included studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) checklists for cohort studies and randomized control trials. Data extraction focused on various factors including population and CM (type, chronicity, severity, and duration) characteristics. Results: The initial search returned 1,688 nonduplicate results, with 417 full text articles reviewed. Twenty-six articles from 16 studies were ultimately included of which 8 examined telomere length and 18 examined DNA methylation. Conclusions: While some heterogeneity of findings was found, evidence supports differential changes in both biomarkers associated with CM. This review enhances understanding of the constellation of biological changes related to CM and consideration of the important role of resilience factors in mitigating risk. Elucidating these factors may highlight targets for future study and intervention development. Clinical Impact Statement Child maltreatment is a serious problem linked to poor mental and physical health outcomes. The mechanisms of these links are not always clear, however, biological changes observed in some maltreated individuals may play a role. Here, we systematically review literature related to 2 biomarkers of interest in maltreated children, telomere length and DNA methylation. Findings are varied; however, overall an association between child maltreatment and changes in both biomarkers is supported. We additionally discuss factors that may confer resilience related to these changes to highlight potential targets for future study and interventions.