Data exist to support the notion that DNA methylation resulting from childhood maltreatment mediates negative outcomes of maltreatment. For example, in the peripheral blood of adults with a diagnosis of PTSD, individuals with a history of childhood abuse demonstrated a specific profile of gene expression which was non-overlapping from that of individuals with a PTSD diagnosis never exposed to abuse (Mehta et al., 2013). These changes in gene expression were associated with altered patterns of DNA methylation at these same gene loci (Mehta et al., 2013). Within individuals with a diagnosis of borderline personality disorder, maltreatment experienced during childhood was positively correlated with BDNF methylation (Perroud et al., 2013). As evidence for increased BDNF methylation contributing to borderline personality disorder symptoms, individuals who responded positively to intensive dialectical behavior therapy exhibited reduced BDNF methylation after completing their treatment regimen relative to their methylation levels prior to treatment (Perroud et al., 2013). Further, single nucleotide polymorphisms (SNPs) have been shown to mediate the relationship between child abuse and adult outcomes. Demethylation of FKBP5 in carriers of the FKBP5 rs1360780 risk allele
