Although epigenome-wide association studies (i.e., EWAS) are now preferred, many studies investigating the associations between maltreatment experiences, DNAm levels and depressive symptoms employed a candidate gene approach, whereby genes are pre-selected on the basis of prior knowledge regarding their neurobiological functions in terms of sensitivity to stress and/or the pathogenesis of depression, such as genes involved in neuroendocrine (FKBP5, NR3C1, OXTR), neurotransmitters (COMT, MAOA, SLC6A3, SLC6A4) and inflammatory pathways (IL6, IL10). This evidence concerns the gene FKBP5 and depressive symptom measurement.