Borderline personality disorder (BPD) is an impairing mental illness and has a core component of emotional dysregulation. Evidence suggests the emotional cascade model describes how this emotional dysregulation leads to engaging in risky and life-threatening behaviors, such as non-suicidal self-injury (NSSI). Specifically, this model describes rumination as a cognitive component that links the emotional and behavioral dysregulation. The current study aimed to expand the model by investigating how individuals with heightened BPD traits engage in NSSI and in cognitive strategies to cope with their negative affect. Specifically, it was investigated whether behaviors like suicide attempts and cognitions differentiated between those with mild/moderate and severe NSSI. Criterion for severe NSSI was hospitalization or medical care because of NSSI. Participants (N = 292) were screened to endorse a history of NSSI and then self-selected to take a self-report survey through Mturk. Correlations and a binomial logistic regression were completed. Results indicated suicide attempts, BPD symptoms, and anger rumination differentiated mild/moderate and severe NSSI. Evidence reinforces the strong relationships between NSSI, suicide attempts, and BPD. Additionally, it reinforces anger rumination as a potential cognitive mechanism in NSSI. Future research can continue to test this model and include other potential thought processes to increase efficiency in assessment and treatment of BPD and NSSI.

Components of Borderline Personality Disorder (BPD) include emotion and cognitive dysregulation. The Emotional Cascade Model (Selby & Joiner, 2009; Selby et al., 2009) suggests negative affect and the cognitive process of rumination could be interchangeably increasing over time, leading to maladaptive behaviors. The current study evaluated negative thinking styles (i.e., anger rumination, sadness rumination, worry, catastrophizing) and thought control strategies (i.e., brooding, reflection, thought suppression) in relation to BPD traits using path analyses in a college student sample (N = 204). Results indicated anger rumination, sadness rumination, and worry indirectly predicted BPD traits through thought suppression, brooding, and reflection. However, catastrophizing did not directly predict any variable. Furthermore, reflection negatively and indirectly predicted BPD traits, while thought suppression and brooding had a positive and indirect effect on BPD traits. Understanding cognitions more in-depth could be influential in the assessment and treatment of BPD. Strengths, limitations, and future directions are discussed.