The relationship between psychological trauma and borderline personality disorder

Borderline personality disorder is a complex disorder with significant morbidity and mortality and considerable controversy regarding its etiology. Numerous theories have been proposed to reclassify the disorder in the "spectrum" of various Axis I illnesses including affective disorders, schizophrenia, impulse disorder, and PTSD. The most recent conceptualization gaining popularity is that BPD is a trauma spectrum disorder. However, the conceptualization of BPD as a trauma spectrum disorder is an oversimplification and does not capture the complexity of the borderline presentation. Individuals with BPD have significantly greater rates of childhood sexual abuse compared to non-BPD patients, with estimates ranging from 40% to 70% for BPD. Parameters of abuse including penetration, multiple perpetrators, sibling and nonrelative perpetrators, duration of abuse, and overall physical abuse rate discriminated BPD from non-BPD groups, indicating these factors require additional attention in both clinical practice and research design. Despite an increased frequency of childhood traumatic experiences in BPD, these events are not unique to BPD. Moreover, childhood abuse has many potential outcomes in adulthood, and it remains unclear how and why a particular pathway ranging from depression, substance abuse, somatization disorder, or personality dysfunction becomes expressed. The association of childhood trauma with BPD diagnosis as well as its separate dimensions including dissociation, impulsive aggression, identity disturbance, and affective instability is limited; however, the domain of impulsive aggression that encompasses self-mutilation yields a stronger connection. Childhood trauma, even if not resulting in PTSD, may have a more pronounced psychological effect in this population and may be of particular importance in a subgroup of BPD patients. The field needs to better understand how certain traumas in certain individuals with particular biological or temperament vulnerabilities interact to produce personality dysfunction. Finally, biological and brain imaging studies are advancing our understanding of the neurobiology of BPD. Inquiry into brain morphology, serotonergic responsivity, and hypothalamic-pituitary-adrenal axis function indicate the biology of individuals with BPD with trauma/PTSD is different than the biology of individuals with only BPD. A deeper understanding of how trauma affects the developing brain and its interaction with genetic vulnerabilities as well as BPD characteristics with biological underpinnings such as impulsivity and affective instability are needed and represent future directions of the field.