Previous research has mostly looked at how disruptions in relationships with primary caregivers during childhood are the most important factor in the origin of the development of borderline personality disorder. In general, previous studies have found that parental death, neglect, unprotectiveness, or separation in a child’s life can all play a factor in the development of borderline personality disorder.
Recently, research there have been a few small case studies which suggest that childhood trauma is the most important factor in the development of borderline personality disorder. These studies showed how the majority of patients diagnosed with borderline personality disorder in these studies reported a history of childhood traumas dealing with physical abuse, sexual abuse or witnessed domestic violence. These studies suggest an association between childhood trauma and the development of borderline personality disorder.
Sample and Population
Researchers chose participants from an extensive longitudinal study of borderline personality disorder in correspondence with closely related disorders like bipolar II affective disorder, antisocial personality disorder, and schizotypal personality disorder. Participants were originally selected from advertisements for volunteers suffering from borderline symptoms or from different mental health settings. In total, 75 individuals were recruited, but only 55 of them, 29 women and 26 men, participated in the study. In this study, 17 women and 4 men had borderline personality disorder (N = 21) and 11 men had borderline traits (N = 11). In regard to non-borderline participants, 6 women and 5 men suffered from bipolar II affective disorder, 3 women and 3 men suffered from antisocial personality disorder, and 3 women and 3 men suffered from schizotypal personality disorder (N = 23). The larger population that researchers want their results to generalize are people with traumatic childhood pasts of abuse that went on to develop borderline personality disorder.
There were five dependent variables in this study. The most important dependent variable was the development of borderline personality disorder. Researchers determined a person to have borderline personality disorder if they scored above 150 on the Borderline Personality Scale and had 5 or more symptoms of borderline personality disorder from the DSM-III. Another dependent variable was the development of borderline traits. Researchers determined a person to have borderline traits if they scored above 130 on the Borderline Personality Scale and had 4 or more symptoms of borderline personality disorder from the DSM-III. Two more dependent variables were the development of antisocial personality disorder and the development of schizotypal personality disorder. Researchers determined a person to have antisocial or schizotypal personality disorders if they met the criteria for the disorders according to the DSM-III. The last dependent variable was the development of bipolar II personality disorder. Researchers determined a person to have bipolar II personality disorder if they met the requirements for the disorder according to Research Diagnostic Criteria.
There was one independent variable in this study. The dependent variable in this study was the level of childhood trauma experienced. Researchers interviewed subjects and applied positive indexes for each occurrence of trauma (physical abuse, sexual abuse, or witnessing domestic violence) that happened during each of three different stages of the participant’s childhood (early childhood, latency, and adolescence). When participants were abused by different people, additional positive scores were added for each abuser in the different stages of childhood. Scoring was on a relative scale from 0 to 9 with zero being no trauma at any developmental stages and nine being all three traumas at all three developmental stages or multiple abusers in one or more developmental stages.
The control in this study was having all the subjects come from a longitudinal borderline personality study where all the participants had borderline symptoms.
The study showed Participants with borderline personality disorder were the most likely to have an abusive childhood history, borderline traits were less likely to, and non-borderline disorders were the least likely to. Almost all of the participants with borderline personality disorder described major childhood trauma, witnessing domestic violence, and being sexually abused. Borderline personality disorder participants were more likely to have abuse in latency than participants with different disorders in the study.
Participants with borderline personalities had more abusive encounters, more types of trauma, earlier onset of abuse, and were abused for longer amounts of time; collectively these results allowed for these participant’s higher trauma scores.
Strengths and Limitations
One of the strengths of this study was that during the interview process researchers had participants give extremely detailed stories of their passed trauma, rather than have them answer yes or no to questions about trauma. This way of interviewing allowed for more credible data. Another strength of this experiment was the conservative way in which they scored trauma in each developmental stage. The researchers were able to account for many confounds by adding additional positive indexes to multiple abusers in different stages and adding negative indexes where certain abuses weren’t considered, like culturally acceptable corporal punishment and fighting or consensual explorative sex with peers.
One of the limitations of this study was the small sample size. The researchers should do the same study using a larger sample size in order to make the results more reliable. Another limitation is the unproportioned ratio of men and women studied for both borderline personality disorder and borderline traits. Borderline personality disorder participants were mostly woman and borderline traits were all men. To make the data more reliable the researchers should find a way to even out the ratios of men to women for those two disorders.