Background: The distinction between complex post-traumatic stress disorder (CPTSD) and borderline personality disorder (BPD) remains contested. Overlap in affective dysregulation, relational disturbance, and negative self-concept has led to claims that CPTSD reflects PTSD-BPD comorbidity or a milder borderline variant. Evidence from low-and middle-income countries including South Africa, where trauma experiences are fre-quent, is limited. Objective: To test whether CPTSD is empirically distinguishable from BPD and whether borderline features emerge independently of CPTSD symptoms. Method: Participants were 449 university students (79% female; age M = 21.46). CPTSD was assessed with the International Trauma Questionnaire; BPD via self-report and adapted clinician-rated instruments from the Structured Clinical Interview for DSM-5 Personality Disorders. Latent class analyses were conducted in the full sample and a childhood trauma exposed subsample (n = 202). Distal outcomes included DSM-5 PTSD, depression, and childhood trauma severity. Results: Five classes emerged in the full sample and four in the trauma exposed sub-sample. A CPTSD-only class was identified in both models, whereas a standalone BPD class did not emerge. BPD symptoms clustered within a CPTSD-BPD class, indicating asymmetric overlap. This class showed the highest depressive severity and childhood trauma exposure. Conclusions: CPTSD was distinguishable from BPD, but co-occurrence was common. Borderline features did not arise independently of CPTSD, suggesting BPD may repre-sent a more severe or developmentally specific configuration within complex trauma presentations.
Rink et al. (2026) studied this question.