ABSTRACT
Childhood maltreatment (CM) is a pervasive public health issue in Australia, strongly associated with post-traumatic stress disorder (PTSD) and intimate partner violence (IPV) victimisation in adulthood. However, borderline personality disorder (BPD) remains an overlooked intermediary in this pathway, despite sharing aetiological roots and symptom overlap with PTSD. This study examined whether BPD and PTSD serially mediate the association between CM and IPV victimisation in adult Australian women. A sample of 123 self-identified female IPV victims completed validated self-report measures assessing CM, BPD features, PTSD symptoms, and IPV experiences. Serial mediation analysis indicated that CM was associated with BPD features, which in turn were associated with more severe PTSD symptomatology, subsequently associated with increased IPV victimisation. CM was also directly associated with IPV victimisation, indicating partial mediation. These findings challenge conventional diagnostic assumptions and suggest many IPV victims may receive incomplete treatment when BPD features are not assessed alongside PTSD. Results underscore the importance of comprehensive screening for both BPD and PTSD in trauma-exposed populations. Early identification and destigmatised assessment of BPD, combined with trauma-informed interventions, may reduce long-term psychiatric consequences and reduce the risk of revictimisation.