Examining the Role of Negative Emotions in Mediating the Association between Trauma and BPD Features in a Community Population Using Structural Equation Modeling

Background/Purpose: Borderline Personality Disorder (BPD) is a debilitating clinical disorder characterized by pervasive instability in interpersonal relationships, self-image, and emotions. Extant research reports a high prevalence of childhood trauma among BPD individuals, yet etiological mechanisms remain unclear. Understanding the link between trauma and BPD is key to developing targeted treatment to diverse BPD populations. This study investigates the association between self-reported trauma and BPD features, hypothesizing a significant association between trauma and BPD features, partially mediated through negative emotions.

Methods: Using a cross-sectional survey design we recruited 100 community participants via Amazon.com’s Mechanical Turk System, an online platform for recruiting subjects for simple projects. BPD features were measured by the short version of the Borderline Symptoms List (BSL-23), trauma symptoms by using Brief Trauma Questionnaire (BTQ), and positive and negative dimensions of affects were assessed using the Positive and Negative Affect Schedule.

Analyses: After examining initial descriptive findings, simple linear regression models were employed to test the direct effects of both negative emotions and trauma on BPD features. Emotions and trauma scores were included as primary predictors, BPD feature scores were the outcome variable, and basic demographics were covariates. Mediation analyses were conducted using structural equation modeling, where the indirect effects (from trauma history to negative emotions, and from negative emotions to BPD features) were tested by a bootstrapping method considering its advantage of not making distributional assumptions.

Results: On average, participants reported low BPD features (Mean=.95, SD=.95) and little experience of both childhood abuse (Mean=1.29, SD=1.97) and other life threats or injuries (Mean=1.43, SD=2). Pearson’s correlations indicated that trauma history, negative emotions and BPD features were all significantly correlated, where higher negative emotions and more trauma history were related to higher BPD features. Linear regression results with both predictors showed that only negative emotions significantly predicted BPD features, controlling for demographic covariates (b=19.72, t=18.24, p<.0001). This model was significant, explaining approximately 87% of variance in participants’ BPD features. Mediation analysis revealed that the indirect effects (from trauma to negative emotions and from negative emotions to BPD features) and total effects were significant. Negative emotions fully mediated the path from interpersonal abuse to BPD features (Db=3.21, z=2.96, p=.03) and from non-interpersonal life injury to BPD features (Db=3.61, z=4.08, p<.0001).

 Conclusion and Implications: Overall, trauma experience is critical in accounting for BPD features although no causal claim can be made based on current results. Moreover, negative emptions appear to be a key underlying mechanism that explains the link between trauma and BPD features. Despite the limitations of small sample size and self-report measures, our study sheds light on an intertwined web among trauma, negative emotions and BPD features. Implications for future practice: (1) Assessment and treatment of trauma symptoms should be integrated into traditional BPD treatment, and (2) emotional difficulties (e.g. negative emotions) should be targeted when treating trauma and BPD symptoms. Future research can incorporate structured interviews and more comprehensive trauma measures in order to disentangle the causal effect of trauma on BPD development and further decipher the mechanisms.