BDNF and Borderline personality disorder: One previous study of participants with borderline personality disorders (n=115) suggested an association between poorer response to intensive dialectical behaviour therapy and increases in DNA methylation of the brain-derived neurotrophic factor gene.31 Another study of veterans with posttraumatic stress disorder (n=16) found that higher pretreatment glucocorticoid-related NR3C1 methylation predicted treatment outcome, whereas FKBP5 gene methylation decreased across treatment time in association with recovery.32 However, some participants were also medicated in both studies.