Introduction: Children and adolescents with out-of-home placement are at a particularly high risk to experience early life adversity (ELA) with potential consequences for neurodevelopmental trajectories. These effects might further depend on gene-environment interactions, and may be mediated through epigenetic modifications, including DNA methylation (DNAm). The oxytocinergic system is a promising candidate in this context due to its essential role in mitigating the neurological impacts of traumas, promoting social and physical bonding, and enhancing resilience. Thus, the aim of this study was to investigate the interplay of ELA with the oxytocinergic systemin a high-risk sample of young Swiss adults with a history of youth residential care.
Method: A sample of 117 young adults with previous youth residential care placements (32% women, M Age=26.3±3.6 years) provided blood samples for genetic and epigenetic analyzes. Blood samples were genotyped and epigenotyped using the Illumina GSA Beadchip GSA MD and Illumina Infinium MethylationEPIC BeadChip Microarray, respectively. As index of ELA, childhood abuse and neglect was measured using the Childhood Trauma Questionnaire.
Results: Data is currently analyzed according to our preregistration (https://archive.org/details/osf-registrations-e86xs-v1). We examine the association of plasma oxytocin, ELA, genotype, and gene by environment interactions with DNAm of genes encoding for oxytocinergic genes, including oxytocin (OXT), oxytocin receptor (OXTR), and cluster of differentiation 38 (CD38).
Discussion: Out-of-home placed children and adolescents are at a particularly high risk for adverse outcomes. The findings might generate novel insight into a potential link between ELA and the oxytocinergic pathway in this vulnerable group.

Introduction: Childhood maltreatment (CM) has long-lasting effects on physical and mental health. Epigenetic processes, like DNA methylation (DNAm), might mediate this link. While the differential impact of CM types on psychopathology has been studied repeatedly, less is known about their impact on specific DNAm patterns. While first evidence suggests that different forms of CM can share common but also exhibit distinct epigenetic signatures in youth from deprived environments (Cecil et al., 2016), it is unclear whether these results generalize to other high-risk samples.
Objective: We thus aim to replicate the results reported by Cecil and colleagues in an independent sample of N=117 previously institutionalized Swiss young adults (32% women, age mean = 26.3, SD = 3.6 years). Participants completed the Childhood Trauma Questionnaire (CTQ) and we assessed DNAm in blood cells using the Illumina Infinium MethylationEPIC BeadChip Microarray.
Results: Overall, 77.78% reported at least moderate to severe experiences in at least one of the subscales of the CTQ (i.e., emotional neglect, physical neglect, emotional abuse, physical abuse, sexual abuse). Following our preregistered analysis plan, we try to replicate results by Cecil and colleagues that show that (A) the different subtypes of CM display unique associations to DNAm of specific CpG sites (unique impact of CM types on DNAm) and (B) there are DNAm patterns that are commonly related to all types of CM (common impact of CM on DNAm independent of CM type). Data analyses are ongoing and final results will be presented and discussed at the conference.

Introduction: Complex PTSD related to lifetime interpersonal violence (physical and sexual abuse and domestic violence exposure and victimization) has been associated with hypocortisolism and decreased glucocorticoid receptor gene methylation in multiple studies.
Methods: This presentation summarizes findings across 8/12 years of prospective, longitudinal study of 51 mother-toddler dyads (mean age 26.7 months SD 8.8) who remained for the duration of the study with complete data using multiple linear regression among other methods.
Results: Maternal and child decreased methylation of the glucocorticoid receptor gene were positively correlated in early childhood and significantly associated with increased aggression during middle childhood. Cortisol reactivity across time was more complex showing an eventual decoupling of subjective stress and cortisol reactivity in school-age children (mean age 7 years, SD 1.1), yet similarly with associations to aggressive behavior.
Conclusions: Findings of this study have implications for the understanding of intergenerational transmission of violence and related psychopathology and intervention, and merit subsequent study.